Physics Letters B 793 (2019) 499–519 Contents lists available at ScienceDirect Physics Letters B www.elsevier.com/locate/physletb Search √ for invisible Higgs boson decays in vector boson fusion at s = 13 TeV with the ATLAS detector .The ATLAS Collaboration  a r t i c l e i n f o a b s t r a c t Article history: We report a search for Higgs bosons that are produced via vector boson fusion and subsequently Received 18 September 2018 decay into invisible particles. The experimental signature is an energetic jet pair with invariant mass Received in revised form 12 February 2019 TeV and O (100) GeV missing transverse momentum. The analysis uses 36.1 fb−1 of pp collision of O (1) √ Accepted 9 April 2019 data at s = 13 TeV recorded by the ATLAS detector at the LHC. In the signal region the 2252 observed Available online 15 April 2019 events are consistent with the background estimation. Assuming a 125 GeV scalar particle with Standard Editor: M. Doser Model cross sections, the upper limit on the branching fraction of the Higgs boson decay into invisible particles is 0.37 at 95% confidence level where 0.28 was expected. This limit is interpreted in Higgs portal models to set bounds on the wimp–nucleon scattering cross section. We also consider invisible decays of additional scalar bosons with masses up to 3 TeV for which the upper limits on the cross section times branching fraction are in the range of 0.3–1.7 pb. © 2019 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). Funded by SCOAP3 . 1. Introduction  missis the O(100) GeV value of the missing transverse momentum cess ET that corresponds to the Higgs boson p T . The VBF topology We present a search for the decays of the Higgs boson [1,2], offers a powerful rejection of the strongly produced2 backgrounds produced via the vector boson fusion (VBF) process [3,4], into due to single vector boson plus two jets, and the multijet back- invisible particles (χ χ̄ ) with an anomalous and sizable O (10)% ground produced from QCD processes. In this analysis, the Higgs branching fraction. The hypothesis under consideration [5–16] is production via the gluon fusion mechanism is subdominant to VBF that the Higgs boson might decay into a pair of weakly interacting and is considered as part of the signal. massive particles (wimp) [17,18], which may explain the nature of Direct searches for invisible Higgs decays look for an excess of dark matter (see Ref. [19] and the references therein). The search events over Standard Model expectations. The absence of an excess carried out for the 125 GeV Higgs boson is repeated for hypothet- is interpreted as an upper limit on the branching fraction of invis- ical scalars with masses up to 3 TeV. The search is independent ible decays (Binv ) assuming the Standard Model production cross on the decay of the mediator because the final state particles are section [20] of the 125 GeV Higgs boson. Other published results invisible to the detector, while it is dependent on its E Tmiss distri- have targeted a variety of production mechanisms—gluon fusion, bution (defined below) because that quantity is reflective of the VBF, W or Z associated production [21–25]—to set upper limits on mediator’s p T distribution. Binv . The best limits are from the statistical combination of search The data sample corresponds to an integrated √ luminosity of results for which ATLAS reports an observed (expected) limit of 36.1 fb−1 of proton-proton (pp) collisions at s = 13 TeV recorded 0.26 (0.17) [26] and CMS reports 0.26 (0.20) [27] at 95% confi- by the ATLAS detector at the LHC in 2015 and 2016. The ex- dence level (CL). For these combinations the single input with the perimental signature of the VBF production process is a pair of highest expected sensitivity is VBF, the channel pursued here. For energetic quark jets with a wide gap in pseudorapidity (η ) cor- the VBF channel using Run-1 data, ATLAS reports 0.28 (0.31) [28] responding to the O (1) TeV value of the invariant mass (m j j ) of and CMS reports 0.43 (0.31) [29]. In a more recent update of the the highest-p T jets in the event.1 The signature for the decay pro- VBF channel using Run-2 data, ATLAS reports 0.37 (0.28) [this pa- per] CMS reports 0.33 (0.25) [27]. Global fits to the measurements of visible decay channels of  E-mail address: atlas.publications@cern.ch. 1 the Higgs boson place indirect constraints on the beyond-the-SM ATLAS uses a right-handed coordinate system with its origin at the nominal interaction point in the center of the detector and the z-axis along the beam di- rection. The x-axis points from the interaction point to the center of the LHC ring; 2 the y-axis points upward. Cylindrical coordinates (r , φ) are used in the transverse For the W and Z background processes in this paper, electroweak (EW) refers plane, where φ is the azimuthal angle around the z-axis. The pseudorapidity is de- to diagrams that are of O (αew 4 ) or greater, while strong refers to diagrams that are fined as η = − ln(tan (θ/2)), where θ is the polar angle. of O (αs2 ) or greater accompanied by O (αew 2 ). https://doi.org/10.1016/j.physletb.2019.04.024 0370-2693/© 2019 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). Funded by SCOAP3 . 500 The ATLAS Collaboration / Physics Letters B 793 (2019) 499–519 decay branching fraction Bbsm . The Bbsm is the sum of Binv that (muons) must have p T > 7 GeV, |η| < 2.47 (2.5), and satisfy an iso- represents invisible decays and Bundet that represents the channels lation requirement. Electrons are reconstructed by matching clus- that are undetected, i.e., those that are not included in the follow- tered energy deposits in the electromagnetic calorimeter to tracks ing combination. For Bbsm using Run-1 data, ATLAS reports 0.49 from the inner detector [41,42] and muons by matching inner de- (0.48) [30] and CMS reports 0.57 (0.52) [31] with similar but not tector and muon spectrometer tracks [43]. For electrons (muons) identical assumptions. A combination of ATLAS and CMS results with a p T value of at least 30 GeV (20-100 GeV), the reconstruction using Run-1 data gives 0.34 (0.39) [32]. In a more recent update efficiency 80% (96%) with a rejection factor of around 500 (600). using Run-2 data, CMS reports an observed limit on Bundet of 0.38 All leptons must originate from the primary vertex. [33]. As noted in Ref. [28], there is complementarity between the Jets are reconstructed from topological clusters in the calorime- direct search for invisible Higgs decays and the indirect constraints ters using the anti-kt algorithm [44] with a radius parameter from the global fits. R = 0.4. Jets must have p T > 20 GeV and |η| < 4.5. The subset of In this analysis, several changes and improvements are made jets with p T < 60 GeV and |η| < 2.4 are jet vertex tagged (jvt) [45] with respect to the previous ATLAS paper on this topic [28]. The to suppress pileup effects, using tracking and vertexing. The jvt is trigger and hadronic objects are defined considering the simul- 92% efficient for the jets in the signal process from the primary in- taneous pp collisions in the same and nearby bunch crossings teraction with a rejection factor of around 100 for pileup jets with (pileup) (Section 2). The leading backgrounds are simulated using p T value in the range of 20-50 GeV [45]. state-of-the-art QCD predictions (Section 3). The event selections Cleaning requirements help suppress non-collision backgrounds are changed to retain a good sensitivity despite the higher pileup. [46]. Fake jets due to noisy cells are removed by requiring a good The analysis extracts the signal yield using a binned likelihood fit fit to the expected pulse shape for each constituent calorimeter to the m j j spectrum in 3 bins to increase the signal sensitivity cell. Fake jets induced by beam-halo interactions with the LHC col- (Section 4). The estimation of the important and dominant back- limators are removed by requirements on their energy distribution ground for the Z → νν process (denoted Z νν ) relies only on the and the fraction of their constituent tracks that originate from the Z ee and Z μμ control samples, and is not affected by theoretical un- primary vertex. certainties of the W -to- Z extrapolation (Section 5). The systematic In events with identified leptons, an overlap removal procedure uncertainties are evaluated separately for each m j j bin (Section 6). is applied to resolve the ambiguities in cases where a jet is also The search is repeated for other scalars with masses up to 3 TeV, identified in the same η -φ area, which could occur in situations which can easily be reinterpreted for models not considered in this such as having a heavy-flavor hadron decay within a jet [47]. The Letter (Section 7). Several aspects of the analysis have not changed lepton–jet overlap in R distance3 is resolved sequentially as fol- compared to the ATLAS Run-1 analysis—e.g., subdetector descrip- lows. If an electron is near a jet with R < 0.2, the jet is removed tions, transfer factor method, Higgs portal models—and details of to avoid the double counting of electron energy deposits. If a re- these may be found in Ref. [28]. maining jet is near an electron with 0.2 ≤ R < 0.4, the electron is removed. If a muon is near a jet with R < 0.4 and the jet 2. Detector, trigger, and analysis objects is associated with at least (less than) three charged tracks with p T > 500 MeV, the muon (jet) is removed. ATLAS is a multipurpose particle physics detector with a The E Tmiss variable is the magnitude  of the negative vector sum forward–backward symmetric cylindrical geometry consisting of a of the transverse momenta, − i p  T,i , where i represents both tracking system, electromagnetic and hadronic calorimeters, and a the “hard objects” and the “soft term.” The hard objects consist muon system [34]. of leptons and jets, which are individually reconstructed and cal- The trigger to record events in the sample containing the VBF ibrated; the list excludes pileup jets, which are removed by a jvt signal candidates used a two-level E Tmiss algorithm with thresholds requirement. The soft term is formed from inner detector tracks adjusted throughout the data-taking period to cope with varying not associated with the hard objects, but matched to the primary levels of pileup [35,36]. The level-1 system used coarse-granularity vertex. In the search region, the E Tmiss produced by the Higgs decay analog sums of the energy deposits in the calorimeter towers to is balanced in the transverse plane by the dijet system. require E Tmiss > 50 GeV. The second-level high level trigger sys- The jvt procedure is intended to remove pileup jets, but can tem [37] used jets that are reconstructed from calibrated clusters cause large fake E Tmiss if it removes a high-p T jet from the hard of cell energies [38] and requires E Tmiss > 70–110 GeV depending scatter, e.g., a jet from a p T -balanced three-jet event.  In order on the luminosity and the pileup level. The trigger efficiency [39] to reduce this, a correlated quantity H Tmiss —defined as | j p  T, j | , for signal events is 98% for E Tmiss > 180 GeV when comparing the where j represents all jets without the jvt requirement—is re- trigger selection with the offline E Tmiss definition that contains ad- quired to be H Tmiss > 150 GeV. In the three-jet example, H Tmiss ditional corrections. would be near zero. The triggers to record the control samples for background stud- The E Tmiss significance (S met ) is used only in events with one identified electron in the final state and is defined as ies used lepton and jet algorithms [40]. The samples with leptonic √ W and Z decays were collected with a single-electron or -muon E Tmiss / p T, j 1 + p T, j 2 + p T,e , where the p T quantities are for leading trigger with p T > 24 GeV (26 GeV) and an isolation requirement in jet ( j 1 ), subleading jet ( j 2 ), and electron, respectively. The use of 2015 (towards the end of 2016). The sample of multijet events was this quantity to reduce the contamination from jets misidentified collected using a set of low-threshold single-jet triggers with large as electrons is discussed in Section 5. prescale values to keep the event rate relatively low. For each event, a vertex is reconstructed from two or more 3. Event simulation associated tracks (t) with p T > 400 MeV. If multiple  vertices are 2 present, we consider the one with the largest t ( p T ,t ) as the Monte Carlo simulation (MC) consists of an event generation primary vertex of our candidates. followed by detector simulation [48] using geant4 [49]. Simulated Leptons ( = e , μ) are identified to help characterize events events were corrected for the small differences between data and with leptonic final states from decays of vector bosons. Since the signal process contains no leptons, such events are used for the  background estimation, which is described in Section 5. Electrons 3 The distance variable is defined as R= ( η)2 + ( φ)2 . The ATLAS Collaboration / Physics Letters B 793 (2019) 499–519 501 MC in the trigger, the lepton identification efficiency, and the jet Table 1 energy scale and resolution using dedicated data samples. Event yields in the signal region (SR) and control regions (CR) summed over lep- ton charge and flavor. The yields are the prefit values for m j j > 1 TeV. The observed For the signal process, the VBF events were generated at next- data (N), the background estimate (B), and the signal (S for m H = 125 GeV with to-leading order (NLO) in QCD using powheg-box2 [50]; inclusive Binv = 1) are given. The B and S values for individual processes are rounded to a NLO electroweak corrections were applied using hawk [51]. The precision commensurate with the sampling uncertainty associated with the finite generated events were interfaced with pythia8 [52] for hadroniza- MC sample size. For all processes the fractions of electroweak production [ew] are tion and showering, using the aznlo tune [53] and the nnpdf3.0 given. “Other” is defined in the text. NNLO PDF set [54]. The gluon fusion events were generated using Description SR W CR Z CR powheg-nnlops [55] with the pdf4lhc15 PDF set [56] interfaced to Yield [ew] Yield [ew] Yield [ew] a fast detector simulation [57–59]. The cross section for ggF (VBF) N, observed 2252 1602 166 was computed at N3 LO (NNLO) in QCD and NLO (NLO) in elec- B, expected 2243 1648 183 troweak. The showering simulation followed the same procedure Z → νν 1111 [18%] – – Z → ee , μμ 12 [9%] 38 [9%] 181 [23%] as for the VBF sample. For both the VBF and gluon fusion events, Z →ττ 10 [16%] 11 [16%] – the H → Z Z ∗ → 4ν process is included in the sample as invisible W → e ν , μν 540 [16%] 1400 [30%] – decays of the Higgs boson. Additional scalars with masses up to W →τν 533 [20%] 130 [34%] – 3 TeV were simulated as described above for VBF signal process, Other 36 67 2 assuming a full width of 4 MeV. S, signal 1070 – – The W and Z events were generated using sherpa2.2.1 [60] with VBF 930 – – comix [61] and openloops [62] matrix-element generators, and Gluon fusion 140 – – merged with sherpa parton shower [63] using the me+ps@nlo pre- scription [64]. The nnpdf3.0 NNLO PDF set was used. In terms of the order of the various processes, the strong production was cal- • no additional jets with p T > 25 GeV, culated at NLO for up to two jets and leading order (LO) for the • E Tmiss > 180 GeV, third and fourth jets. The electroweak production was calculated • H Tmiss > 150 GeV. at LO for the second and third jets. The levels of the interference between electroweak and strong processes were computed with The two jets are required to have the following properties: madgraph5_amc@nlo [65]. The interference on the total expected •  miss , | φ j-met | > 1, not be aligned with E background is only 0.1% and thus neglected. T Other potential background processes involve top quarks, di- • not be back-to-back, | φ j j | < 1.8, bosons, and multijets. Top quarks and dibosons were generated • be well separated in η , | η j j | > 4.8, with powheg interfaced with pythia and evtgen [66], which sim- • be in opposite η hemispheres, η j 1 · η j 2 < 0, ulate the heavy-flavor decays. The diboson backgrounds include • m j j > 1 TeV. electroweak-mediated processes. The multijet estimate does not directly use the MC. The SR includes background events containing a W or Z plus two To each hard-scatter MC event, pileup collisions (30 on average) jets, where the W decays into e ν , μν , and τ ν , and the Z decays were added to mimic the environment of the LHC. The pileup col- into two neutrinos. Here the leptons from the W decays are not lisions, simulated with pythia8 [52] using mstw2008 PDF [67] and reconstructed since they would otherwise be rejected by the se- the a2 set of tuned parameters [68], were subsequently reweighted lection. to reproduce the pileup distribution in data. Table 1 gives the prefit SR yields in the first column. The VBF The sizes of the MC samples vary depending on the process. production process gives the biggest contribution (87%) to the sig- The effective luminosity ranges for the MC samples varies depend- nal sample (fixed as Binv = 1). The contribution from gluon fusion ing on the process and on the selections, which are defined in accompanied by parton radiation is small (13%) and other produc- Section 4. For the W process, the MC sample is approximately half tion modes contribute negligibly. The fraction of VBF signal events of that of the data selected for the W control region and also half that pass the signal region event selections, defined as acceptance for the signal region. For the Z process, the MC sample for the Z times reconstruction efficiency, is 0.7%. As is discussed in Sec- subprocess is approximately twice that of data in the Z control re- tion 7, the signal significance is improved by considering three bins gion; the MC sample for Z νν subprocess is approximately the same of m j j defined as follows: 1 < m j j ≤ 1.5 TeV, 1.5 < m j j ≤ 2 TeV, and as that of data in the signal region. m j j > 2 TeV. The prefit S / B ratio (for Binv = 1) in these bins is ap- proximately 0.3, 0.4, 0.8, respectively. For the backgrounds, both the strong production and the EW 4. Event selection production contribute in the SR. The strong production processes contributes more than 70% of the backgrounds in all of the m j j All events must have a primary vertex. The selection listed be- bins. There is variation in the EW fractions for the background low divides the data sample into a signal-enriched search region processes due to a combination of the following factors: known (SR) and background-enriched control regions (CR). The control re- differences in the production diagrams between W and Z , differ- gions and the statistical fit are discussed in detail in Section 5. The ences in kinematic acceptance for the particular W or Z decay, rest of this section focuses on the SR and the prefit event yields.4 and differences in the MC sample size for each EW process. For the SR, an event is required to have 5. Control samples and statistical treatment • no isolated electron or muon, • a leading jet with p T > 80 GeV, The main backgrounds in the SR, comprising of 98% of the • a subleading jet with p T > 50 GeV, background, are the W and Z processes. The minor backgrounds, comprising the remaining 2%, are the diboson, t t̄, and multijet 4 “Prefit” indicates that the event yields are not adjusted according to the statis- processes. Accurate estimation of the W and Z processes is the tical treatment of the background predictions, which is described in the second half biggest challenge of the analysis. The main background yields are of Section 5. “Postfit” labels the quantities that come out of the fit procedure. extracted using dedicated control samples in data. 502 The ATLAS Collaboration / Physics Letters B 793 (2019) 499–519 Fig. 1. Data-to-MC yield comparisons in the 27 subsamples used in the statistical fit. The observed data N (dots) are superimposed on the prefit backgrounds B (stacked histogram with shaded systematic uncertainty bands). The hypothetical signal S (empty blue histogram) is shown on top of B for Binv = 1. The bottom panels show the ratios of N (dots) and B + S (blue line) to B with the systematic uncertainty band shown on the line at 1. The 1, 2, and 3 bin labels corresponds to 1 < m j j ≤ 1.5 TeV, √ 1.5 < m j j ≤ 2 TeV, and m j j > 2 TeV, respectively. The “e fakes” refers to S met < 4 GeV selection and is determined by the fit, so postfit values are shown for the purposes of illustration. The diboson contribution is included in the electroweak (EW) W and Z bosons. This section is organized as follows. First, the two main CR are jets) have high (low) E Tmiss resolution event-by-event. Since S met described and the associated prefit yields are given. Second, the is a proxy for E Tmiss resolution, a passing (failing) selection on fit parameters are defined along with a discussion of the contami- √ S met > 4 GeV provides a W ehigh ν (W elow ν ) subsample depleted (en- nation in the W eν subsample. Third, the fit procedure is described riched) in e fakes. In the fake-enriched W elow ν subsample, about a and the postfit yields are stated. Lastly, the minor backgrounds and third of the events are due to e fakes. (For the W eν process, the the estimation of the multijet processes are described. E Tmiss comes from the neutrino. For this reason, the kinematic bias The W CR requires one identified lepton with a p T threshold in E Tmiss due to the S met selection was found to be negligible at the of 30 GeV, but the selections are otherwise identical to those of 1% level.) The resulting subsamples are tied together by a fixed ra- the SR. The initial ν selection is divided by lepton flavor, charge, √ tio ρfake , which is determined using a separate “pure-fake” region. and, for the e ν final state, a passing  selection on Shigh met > 4 GeV The pure-fake region (F eν ) is defined by a selection on the elec- to define four W CR subsamples W μ+ ν , W μ− ν , W e+ ν , W ehigh −ν . tron likelihood (Le ). Since Le is optimized to separate electrons The complementary failed  selection on  S met defines the two “fake- enriched” subsamples W elow low miss from backgrounds originating from dijet processes [41], requiring + ν , W e − ν . The E T is calculated by adding the calibrated leptons to the sum. that the candidate’s Le value fail the tight definition [42], while The Z CR is based on the same selection criteria as the SR, but satisfying a looser definition, selects the F eν data sample. As done  the lepton veto is replaced by the requirement of two same-flavor above, the S met selection creates two subsamples F ehigh low ν , F eν . opposite-sign leptons with |m − m Z | < 25 GeV. The sample is The F elow high ν -to-F e ν ratio of the number of events in data is ρfake , divided by lepton flavor, but not by charge ( Z ee , Z μμ ). The lead- with the small amount of prompt W contamination subtracted us- ing lepton-p T threshold is the same as above, and the subleading ing MC. lepton-p T threshold is 7 GeV. The E Tmiss is calculated as is done Model testing uses a profile likelihood-ratio test statistic [69] in above. the CLs -modified frequentist formalism [70]. The statistical treat- Table 1 gives the prefit CR yields for the inclusive selection of ment considers a total of 27 bins: three m j j bins for each of nine m j j > 1 TeV for the W ( Z ) CR in the third (fourth) columns. These subsamples (one for the SR, four for the W CR, two for the fake- prefit yields are the inputs for the statistical fit described below. enriched subsamples, two for the Z CR). A maximum-likelihood fit to the observed data in each m j j bin sets an upper limit,5 using The samples are very pure, as the relative contribution of the W a one-sided confidence level, on Binv for the 125 GeV Higgs boson ( Z ) CR is 95% (99%) from W ( Z ) decays. The definitions of the and on the product σscalar vbf · Binv for a scalar of different mass. The main normalizations parameters in the fit are  sr  prefit comparisons of data and MC are shown for all subsamples B estimate = N W cr · B sr W /B W = B W · NW /B W cr sr cr cr in Fig. 1.  W  The fit procedure extracts the nine floating parameters intro- B Z estimate = N Z · B Z / B Z = B Z · N Z / B Z , sr cr sr cr sr cr cr     duced above (βW , βZ , νfake for each m j j bin). After the fit, the α transfer β normalization postfit β parameters are consistent with the SM prefit prediction where the event yields are for the observed data (N) and the MC within their 1 σ uncertainties. The postfit comparisons of data and estimate of the background (B). The transfer factor α is the SR-to- expected backgrounds are shown in Fig. 2 for the two key vari- CR ratio of the MC yields, and is a quantity useful for visualizing ables, m j j and E Tmiss , for the W and Z CR. The m j j (E Tmiss ) plot how the systematic uncertainties partially cancel out. The normal- groups the backgrounds to show the dependence of the distribu- ization β is the data-to-MC ratio in the CR, which is extracted from tion shape on the production mechanism (final state). the fit. The analysis is performed in three m j j bins i, so i also in- dexes α and β . 5 For the W ehigh ν subsample in the W CR, a yield parameter νfake The likelihood is a product of Poisson functions, one for each sample of N is introduced to quantify the “e fakes,” the group of electron can- events while expecting λ, a Gaussian function for each systematic uncertainty, and a Poisson function for the number of MC events. In the simple scenario with only didates that are not prompt electrons. This contamination occurs W and Z backgrounds, the λ for the SR would be S + βW · B W Z sr + βZ · B sr , with each most often when a jet from a multijet event identified as an elec- quantity multiplied by the response function for a systematic uncertainty. For the tron candidate. The underlying idea is that the W decays (multi- W CR it is βW · B W Z cr and for the Z CR it is βZ · B cr . See, e.g., Ref. [71]. The ATLAS Collaboration / Physics Letters B 793 (2019) 499–519 503 Fig. 3. Distribution of event yields in the multijet validation region for m j j (left) and E Tmiss (right). The m j j plot shows the 100 < E Tmiss < 120 GeV subset of the right plot as indicated by the arrow. The N observed data (dots) are superimposed on the sum of the B backgrounds (stacked histogram). The systematic uncertainty band applies only to the multijet component. The statistical uncertainties are relatively large because of the weighting of the trigger samples with large prescale values. See the caption of Fig. 2 for other plotting details. comparison of the predictions and the data in the VR shows good agreement (Fig. 3). The multijet component is obtained using the rebalance-and-smear method with the associated systematic un- Fig. 2. Distribution of event yields in the Z (top) and W (bottom) control regions. certainty bands, while the non-multijet components are obtained The postfit normalizations for m j j (left) and E Tmiss (right) are summed over the sub- using MC. samples. The E Tmiss distributions start at 180 GeV as indicated. The observed data N (dots) are superimposed on the sum of the backgrounds B (stacked histogram with shaded systematic uncertainty bands). The breakdown of the B is given in the lower 6. Uncertainties left box in each panel. The bottom panels show the ratios of N to B with the sys- tematic uncertainty band shown on the line at 1. The “other,” as listed in Table 1, Experimental and theoretical sources of uncertainties as well as contribute a few events at low values of m j j and E Tmiss , and are omitted. The last bin in each plot contains the overflow. the correlations between the various sources are described. The re- sulting impact of the uncertainties on the yields and on the signal sensitivity is summarized later in Table 2. The postfit value of νfake (the product ρfake · νfake ) is the abso- Experimental sources of uncertainty are due mainly to the jet lute number of e fake events in the W ehigh ν (W elow ν ) subsamples. energy scale and resolution [75], E Tmiss soft term [76], and lep- Since there is a νfake parameter for each bin i, the m j j shape is ton measurements [42,43]. In order to reduce fluctuations due to also predicted. Apart from determining the ρfake value, which is limited MC sample size, the uncertainties in number of expected fixed in the fit, F eν is not part of the fit model. We note that the ± events for the variations of jet energy scale and resolution for the W ehigh low ν -W e ν samples are split by charge, because W production strong and electroweak background samples are averaged. This is is not symmetric in pp collisions. However, the same νfake param- eter is used for both charges because the e fakes are expected to motivated by the similarities of the kinematics and the detector ef- be symmetric in charge since they originate mostly from multijet fects for the two production processes for each m j j bin. The uncer- events. tainty related to lepton identification or veto has a non-negligible The remaining processes—top quarks, dibosons, multijets— (negligible) effect on αW (αZ ) because of the following scenarios. contribute negligibly to the SR (called “other” in Table 1). The The W ν background is significant in the SR, which results in an first two are estimated with MC using nominal cross sections. The uncertainty for the cases related to the lepton veto. The Z back- multijet contribution is very small, but it is a difficult process to ground is negligible in the SR, because the selection requires there estimate. It is a potentially dangerous background because those to be no leptons. events that pass the E Tmiss selection are mostly due to instrumen- The following experimental sources have small or negligible tal effects. impact in the final result. The pileup distribution and luminosity The billionfold-or-more reduction of multijets after the event [77,78] have a relatively small impact. The trigger efficiency mod- selection makes it impractical to simulate, so a data-driven method eling, for both the lepton triggers for the CR and E Tmiss triggers for based on a rebalance-and-smear strategy [72] is used. The assump- the SR, are not listed in Table 2. Their impact on the events yields tion is that the E Tmiss is due to jet mismeasurement in the detector was at the 1% level and their impact on the signal sensitivity are response to jets and neutrinos from heavy-flavor decays [73,74]. found to be negligible. Using the jet-triggered sample, the jet momenta are rebalanced by Theoretical sources of uncertainty are due mainly to scale a kinematic fit, within their experimental uncertainties, to obtain choices in fixed-order matrix-element calculations. For the back- the balanced value of the jets’ p T . The rebalanced jets are smeared ground processes, QCD scales are varied for the resummation according to jet response templates, which are obtained from MC scale (resum.), renormalization scale (renorm.), factorization scale and validated with dijet data. The rebalance-and-smear method (fact.), and ckkw matching scale. The first three scales in the list— predicts both the shape of the E Tmiss distribution and the absolute technically called q2 , μR , μF , respectively—are varied by a factor normalization. The procedure is verified in a φ j j -sideband vali- of two [79,80]. For the ckkw matching scale between the matrix dation region (VR) with 95% purity of QCD multijet events. This element and the parton shower [60], the central value and the VR is defined by 1.8 < | φ j j | < 2.7 and the loosening of the other considered variations are 20+ 10 −5 GeV. The higher-order electroweak requirements (| η j j | > 3, m j j > 0.6 TeV, and allow a third leading corrections to the strongly produced W or Z are found to be neg- jet with 25 < p T < 50 GeV, but no other jets with p T > 25 GeV). The ligible. 504 The ATLAS Collaboration / Physics Letters B 793 (2019) 499–519 Table 2 Sources of uncertainty. The first set shows , the relative improvement of the 95% CL upper limit on Binv when the source of uncertainty is “removed” by fixing it to its best-fit value. The “visual” column shows bars whose lengths from the center tick are proportional to . The second set shows the effect on the yields and the α transfer factors for the 1 < m j j ≤ 1.5 TeV bin. The yields are for the signal process in the SR (S), Z MC in the SR ( B sr cr Z ), and Z MC in the CR ( B Z ). The α Z is given to demonstrate the reduction in the uncertainty in the ratio B sr cr Z / B Z . The individual yields for the W are not shown because the cancellation effects are similar to the Z counterparts. The value for “3rd jet veto” corresponds only to the uncertainty related to jet bin migration for signal processes; the corresponding effect for the background processes are evaluated in the various jet energy and theoretical variations. The abbreviations for the theoretical sources are described in the text. The ‘-’ indicates that the quantity is not applicable. The “combined” rows at the bottom are not simple sums of the rows above because of the metric; the symbols (†, ‡, ) are parenthetically defined in the table. The penultimate (last) row shows the summary impact of removing the systematic uncertainties due to the experimental and theoretical sources (as well as statistical uncertainties of the MC samples). Source Binv improve. [%] using all m j j bins Yields, α changes (%) in 1 < m j j ≤ 1.5 TeV visual S B Zsr B Zcr αZ αW Experimental (†) Jet energy scale 10 12 7 8 8 6 Jet energy resol. 2 2 0 1 1 4 E Tmiss soft term 1 2 2 2 2 2 Lepton id., veto 2 – – – 0 4 Pileup distrib. 1 3 1 2 3 1 Luminosity 0 2 2 2 – – Theoretical (‡) Resum. scale 1 – 2 3 0 2 Renorm., fact. 2 – 20 19 1 2 ckkw matching 4 – 2 3 1 5 PDF 0 1 1 2 1 1 3rd jet veto 2 7 – – – – Statistical MC sample () 12 4 5 9 10 9 Data sample 21 6 5 12 12 6 Combined All † sources 17 All ‡ sources 10 Combine †, ‡ 28 Combine †, ‡,  42 The effects of the theoretical variations are evaluated with a One major difference between Ref. [28] and this paper—with sample of generated MC events prior to reconstruction, which is the former (latter) employing (not employing) the W -to- Z extrap- larger than the reconstructed sample. Moreover, in order to reduce olation strategy—is that we now have a larger Z control sample. fluctuations due to limited MC statistics, the effect of the resum- We found that the final limit result based on the statistical uncer- mation and ckkw variations as a function of m j j are determined tainty of the enlarged Z control sample is similar to the result by a linear fit, using m j j values below the selection for the SR and assuming the theoretical uncertainties on the W -to- Z ratio (in- a sample with loosened selection on η j j and φ j j . We verified cluding the associated MC sample statistical uncertainties). This that an additional systematic uncertainty associated with the ex- being the case, this paper adopts the method that is less depen- trapolation is dominated by the statistical fluctuations in the varied dent on theoretical assumptions. samples. The sources of uncertainty are grouped into the three main For both signal and background, the effects of the choice of a categories given above (Table 2). The impact of each source is mea- parton distribution function (PDF) set have a relatively small im- sured in two ways: (1) on the 95% CL upper limit on Binv and pact. The variations are considered using an ensemble of PDFs (2) on the event yields and α transfer factors. Impact (1) assesses within the nnpdf set [54] and the standard deviation of the distri- the percentage improvement of the Binv limit if that source of un- bution is taken as the uncertainty. certainty is removed after fixing the associated parameter to its For the signal process, the effect of the scale uncertainty on the best-fit value. Impact (2) demonstrates that the systematic uncer- third-jet veto for the gluon fusion plus two-jet contribution is eval- tainties in the individual yields partially cancel out for many of uated using the jet-bin method [81]. The similar effect for the VBF the theoretical sources. However, for many of the experimental contribution is evaluated by comparing the scale varied samples sources the cancellation is not achieved due to limited MC statis- before and after the third-jet veto. The impact on the Higgs signal tics of the varied samples. For example, the effects of varying the yield is dominated by the VBF contribution, which is around 7%. renormalization  and factorization  scales change   the MC yield in Statistical uncertainties are due to the data and MC sample the Z SR B Zsr in Table 2 and the Z CR B Zcr by about 20%, but sizes. the αZ transfer factor changes by only 1%. In Table 2, only the Systematic uncertainties are assumed to be either fully corre- 1 < m j j ≤ 1.5 TeV yields are shown for the purpose of illustrating lated or uncorrelated. The uncertainties from the following sources the partial cancellation in the ratio. in each independent m j j bin are correlated between the SR and In general, the uncertainties are higher with m j j . The MC sam- CR: QCD scales, PDF, and lepton measurements. The theoretical un- ple statistics is the largest source of systematic uncertainties, with certainties due to QCD scales are uncorrelated between the follow- the uncertainty increasing with m j j due to limited number of sim- ing pairs: signal vs. background, electroweak vs. strong production, ulated events. The theory uncertainties are also higher with m j j and W vs. Z production. Theoretical uncertainties are fully uncor- values for the same reason. The experimental jet energy uncer- related between bins of m j j , while the experimental uncertainties tainties are also affected by the limited sample size, with larger are fully correlated, both of which are expected to be conservative fluctuations because of fluctuations that do not cancel for each assumptions. individual systematic variations. For the sources contributing the The ATLAS Collaboration / Physics Letters B 793 (2019) 499–519 505 Fig. 4. Contributions to the relative uncertainty in the transfer factors αZ (left) and αW (right) in the three m j j bins of the SR. The theoretical uncertainties from the sources noted in the legend are combined in quadrature. Fig. 6. Upper limits on (a) the spin-independent wimp–nucleon cross section using Higgs portal interpretations of Binv at 90% CL vs. mwimp and (b) the VBF cross sec- tion times the branching fraction to invisible decays at 95% CL vs. mscalar . The top plot shows results from Ref. [85–87]. Fig. 5. Distribution of event yields in the signal region for m j j (left) and E Tmiss (right). The E Tmiss distributions start at 180 GeV and shows the most sensitive m j j > 2 TeV subset of the SR as indicated by the arrow. The postfit normalizations for m j j (E Tmiss ) The left plot in Fig. 5 also shows that the S / B ratio rises with distributions use separate background, B, normalizations in the three (one) m j j bins increasing m j j values, which motivates our division of the SR into of 1 < m j j ≤ 1.5 TeV, 1.5 < m j j ≤ 2 TeV, and m j j > 2 TeV (m j j > 2 TeV), and sum the multiple bins. The total electroweak contribution in the SR is rela- contributions from W and Z bosons (electroweak and strong production modes). tively small at O (10%) (Table 1), but the much flatter distribution The hypothetical signal S (empty blue histogram) is shown on top of B for Binv = 1. The bottom panels show the ratios of N (dots) and B + S (blue line) to B with the of m j j makes it an important contribution to the final result. As systematic uncertainty band shown on the line at 1. The bin width in the m j j plots noted in Section 5, the background estimation is done indepen- (E Tmiss ) is 500 GeV (50 GeV except for the first bin with the non-zero entry, which is dently for each m j j bin to reduce the dependence on m j j modeling. 20 GeV). See the caption of Fig. 2 for other plotting details. The fit, assuming the 125 GeV Higgsboson, gives  the observed (expected) upper limit on Binv of 0.37 0.28 + 0.11 −0.08 at 95% CL, and   largest uncertainties, the αZ and the αW variations in the three 0.32 0.23 + 0.11 −0.10 at 90% CL, where the uncertainties placed on the m j j bins are shown graphically in Fig. 4. expected limit represent the 1σ variations. With this result, con- The combination of uncertainties from various sources shows nections to wimp dark matter can be made in the context of Higgs that the dominant category has a systematic origin (penultimate portal models [82]. The limit on Binv can be used to set limit row of Table 2). The lack of MC statistical precision for background on the Higgs-wimp coupling by the wimp-nucleon scattering cross processes with m j j > 2 TeV has the largest impact on Binv . We note section formulae (σwimp-nucleon ). In this paper, scalar and Majorana that the values are percent improvements of the final limit on fermion wimp models are considered [11,83,84]. Binv , so they do not add in quadrature or in any such standard The overlay of the interpretation of this result with the statistical combinations. limits from some of the direct detection experiments [85–87] shows the complementarity in coverage (Fig. 6(a)). For the scalar 7. Results and interpretations wimp interpretation   cross  sections  are excluded at values ranging from O 10−42 to O 10−45 cm2 and for the Majorana fermion   The 2252 observed events in the SR are divided among the wimp interpretation the exclusion range is from O 10−45 to  −46  2 three m j j bins defined previously: 952, 667, and 633 events. O 10 cm , depending on the wimp mass. The uncertainty band These values are consistent with the background-only postfit yields in the plot uses an updated computation of the nucleon form fac- of the sum of the background processes of 2100 events, which tors [88]. are divided among the three m j j bins: 850 ± 113, 660 ± 90, and The correlation between Binv and σwimp-nucleon is presented 590 ± 81, respectively. The uncertainty represents the combined ef- in the effective field theory framework assuming that the new- fect due to experimental and theoretical systematic uncertainties. physics scale is O (1) TeV [28], well above the scale probed at the These postfit values are also consistent with the prefit predictions. Higgs boson mass. Adding a renormalizable mechanism for gener- The expected signal yields (for Binv = 1 for VBF and gluon fusion) ating the fermion wimp masses could modify the above-mentioned are 300, 310, and 460, respectively, and the last m j j bin has the correlation [89]. highest sensitivity with S / B ≈ 0.8. In place of the 125 GeV Higgs boson, the same selection is ap- The postfit SR event distributions of m j j and E Tmiss are shown plied to additional scalars with masses (mscalar ) of up to 3 TeV in Fig. 5, and we observe agreement, within uncertainties, between assuming only VBF production. The fraction of VBF signal events the data and the expected backgrounds. that pass the signal region event selections corresponding to the 506 The ATLAS Collaboration / Physics Letters B 793 (2019) 499–519 acceptance times efficiency ranges from 0.6–3%. The signal effi- References ciency for the inclusive m j j > 1 TeV selection increases with the mass of the scalar boson, because the VBF jets is more forward [1] ATLAS Collaboration, Observation of a new particle in the search for the Stan- with higher mass, and thus have more events at higher values of dard Model Higgs boson with the ATLAS detector at the LHC, Phys. Lett. B 716 (2012) 1, arXiv:1207.7214 [hep-ex]. m j j . The limit on σscalar vbf · Binv as a function of mscalar is shown in [2] CMS Collaboration, Observation of a new boson at a mass of 125 GeV with Fig. 6(b). The 95% confidence level upper limits on the cross sec- the CMS experiment at the LHC, Phys. Lett. B 716 (2012) 30, arXiv:1207.7235 tion times branching fraction are in the range of 0.3–1.7 pb. [hep-ex]. [3] S. Dittmaier, C. Mariotti, G. Passarino, R. Tanaka (Eds.), Handbook of LHC Higgs Cross Sections: 1. Inclusive Observables, 2011, CERN-2011-002, arXiv:1101.0593 8. Conclusions [hep-ph]. [4] S. Dittmaier, C. Mariotti, G. Passarino, R. Tanaka (Eds.), Handbook of LHC Higgs Cross Sections: 2. Differential Distributions, 2012, CERN-2012-002, arXiv:1201. A search for Higgs boson decays into invisible particles is 3084 [hep-ph]. presented using the 36.1 fb−1 of pp collision data taken at [5] I. Antoniadis, M. Tuckmantel, F. Zwirner, Phenomenology of a leptonic goldstino √ and invisible Higgs boson decays, Nucl. Phys. B 707 (2005) 215, arXiv:hep-ph/ s = 13 TeV collected in 2015 and 2016 by the ATLAS detector 0410165. at the LHC. The targeted signature is the VBF topology with two [6] N. Arkani-Hamed, S. Dimopoulos, G.R. Dvali, J. March-Russell, Neutrino masses energetic jets with a wide gap in η and large E Tmiss . from large extra dimensions, Phys. Rev. D 65 (2002) 024032, arXiv:hep-ph/ Assuming the Standard Model cross section for the 125 GeV 9811448. Higgs boson, an upper limit of 0.37 is set on Binv at 95% CL. This [7] S. Kanemura, S. Matsumoto, T. Nabeshima, N. Okada, Can WIMP dark matter overcome the nightmare scenario?, Phys. Rev. D 82 (2010) 055026, arXiv:1005. result is interpreted using Higgs portal models to exclude regions 5651 [hep-ph]. in the σwimp-nucleon vs. mwimp parameter  space  to exclude  cross sec- [8] A. Djouadi, O. Lebedev, Y. Mambrini, J. Quevillon, Implications of LHC searches tion values ranging from O 10−42 to O 10−46 cm2 , depending for Higgs–portal dark matter, Phys. Lett. B 709 (2012) 65, arXiv:1112.3299 on the wimp mass and the wimp model. [hep-ph]. [9] R.E. Shrock, M. Suzuki, Invisible decays of Higgs bosons, Phys. Lett. B 110 Searches for invisible decays of scalars with masses of up to (1982) 250. 3 TeV are reported for the first time from ATLAS in the VBF pro- [10] D. Choudhury, D.P. Roy, Signatures of an invisibly decaying Higgs particle at duction mode. These results are rather general and can be used for LHC, Phys. Lett. B 322 (1994) 368, arXiv:hep-ph/9312347. further interpretations. [11] O.J.P. Eboli, D. Zeppenfeld, Observing an invisible Higgs boson, Phys. Lett. B 495 (2000) 147, arXiv:hep-ph/0009158. [12] H. Davoudiasl, T. Han, H.E. Logan, Discovering an invisibly decaying Higgs at Acknowledgements hadron colliders, Phys. Rev. D 71 (2005) 115007, arXiv:hep-ph/0412269. [13] R.M. Godbole, M. Guchait, K. Mazumdar, S. Moretti, D.P. Roy, Search for ‘invis- ible’ Higgs signals at LHC via associated production with gauge bosons, Phys. We thank CERN for the very successful operation of the LHC, Lett. B 571 (2003) 184, arXiv:hep-ph/0304137. as well as the support staff from our institutions without whom [14] D. Ghosh, R. Godbole, M. Guchait, K. Mohan, D. Sengupta, Looking for an in- visible Higgs signal at the LHC, Phys. Lett. B 725 (2013) 344, arXiv:1211.7015 ATLAS could not be operated efficiently. [hep-ph]. We acknowledge the support of ANPCyT, Argentina; YerPhI, Ar- [15] G. Belanger, B. Dumont, U. Ellwanger, J.F. Gunion, S. Kraml, Status of invisible menia; ARC, Australia; BMWFW and FWF, Austria; ANAS, Azer- Higgs decays, Phys. Lett. B 723 (2013) 340, arXiv:1302.5694 [hep-ph]. baijan; SSTC, Belarus; CNPq and FAPESP, Brazil; NSERC, NRC and [16] D. Curtin, R. Essig, S. Gori, P. Jaiswal, A. Katz, Tao Liu, Zhen Liu, D. McKeen, J. Shelton, M. Strassler, Z. Surujon, B. Tweedie, Y.-M. Zhong, Exotic decays of the CFI, Canada; CERN; CONICYT, Chile; CAS, MOST and NSFC, China; 125 GeV Higgs boson, Phys. Rev. D 90 (2014) 075004, arXiv:1312.4992 [hep- COLCIENCIAS, Colombia; MSMT CR, MPO CR and VSC CR, Czech ph]. Republic; DNRF and DNSRC, Denmark; IN2P3-CNRS, CEA-DRF/IRFU, [17] H. Goldberg, Constraint on the photino mass from cosmology, Phys. Rev. Lett. France; SRNSFG, Georgia; BMBF, HGF, and MPG, Germany; GSRT, 50 (1983) 1419. [18] J.R. Ellis, J.S. Hagelin, D.V. Nanopoulos, K.A. Olive, M. Srednicki, Supersymmetric Greece; RGC, Hong Kong SAR, China; ISF and Benoziyo Center, Is- relics from the big bang, Nucl. Phys. B 238 (1984) 453. rael; INFN, Italy; MEXT and JSPS, Japan; CNRST, Morocco; NWO, [19] D. Clowe, et al., A direct empirical proof of the existence of dark matter, Astro- Netherlands; RCN, Norway; MNiSW and NCN, Poland; FCT, Portu- phys. J. 648 (2006) L109, arXiv:astro-ph/0608407. gal; MNE/IFA, Romania; MES of Russia and NRC KI, Russian Fed- [20] D. de Florian, C. Grojean, F. Maltoni, C. Mariotti, A. Nikitenko, M. Pieri, P. Savard, eration; JINR; MESTD, Serbia; MSSR, Slovakia; ARRS and MIZŠ, M. Schumacher, R. Tanaka (Eds.), Handbook of LHC Higgs Cross Sections: 4. Deciphering the Nature of the Higgs Sector, FERMILAB-FN-1025-T, 2016, CERN- Slovenia; DST/NRF, South Africa; MINECO, Spain; SRC and Wallen- 2017-002-M, arXiv:1610.07922 [hep-ph], 2016. berg Foundation, Sweden; SERI, SNSF and Cantons of Bern and [21] ATLAS Collaboration, Search for invisible particles produced in association with √ Geneva, Switzerland; MOST, Taiwan; TAEK, Turkey; STFC, United single-top-quarks in proton-proton collisions at s = 8 TeV with the ATLAS Kingdom; DOE and NSF, United States of America. In addition, in- detector, Eur. Phys. J. C 75 (2015) 79, arXiv:1410.5404 [hep-ex]. [22] CMS Collaboration, Search for invisible decays of Higgs bosons in the vector dividual groups and members have received support from BCKDF, boson fusion and associated ZH production modes, Eur. Phys. J. C 74 (2014) Canarie, CRC and Compute Canada, Canada; COST, ERC, ERDF, Hori- 2980, arXiv:1404.1344 [hep-ex]. zon 2020, and Marie Skłodowska-Curie Actions, European Union; [23] ATLAS Collaboration, Search for invisible decays of the Higgs boson produced in √ Investissements d’ Avenir Labex and Idex, ANR, France; DFG and association with a hadronically decaying vector boson in pp collisions at s = 8 TeV with the ATLAS detector, Eur. Phys. J. C 75 (2015) 337, arXiv:1504.04324 AvH Foundation, Germany; Herakleitos, Thales and Aristeia pro- [hep-ex]. grammes co-financed by EU-ESF and the Greek NSRF, Greece; BSF- [24] CMS Collaboration, Search for dark matter in proton-proton collisions at 8 NSF and GIF, Israel; CERCA Programme Generalitat de Catalunya, TeV with missing transverse momentum and vector boson tagged jets, J. High Spain; The Royal Society and Leverhulme Trust, United Kingdom. Energy Phys. 12 (2016) 083, Erratum: J. High Energy Phys. 08 (2017) 035, arXiv:1607.05764 [hep-ex]. The crucial computing support from all WLCG partners is ac- [25] ATLAS Collaboration, Search for an invisibly decaying Higgs boson or dark mat- knowledged gratefully, in particular from CERN, the ATLAS Tier-1 √ ter candidates produced in association with a Z boson in pp collisions at s = facilities at TRIUMF (Canada), NDGF (Denmark, Norway, Sweden), 13 TeV with the ATLAS detector, Phys. Lett. B 776 (2018) 318, arXiv:1708.09624 CC-IN2P3 (France), KIT/GridKA (Germany), INFN-CNAF (Italy), NL- [hep-ex]. T1 (Netherlands), PIC (Spain), ASGC (Taiwan), RAL (UK) and BNL [26] ATLAS Collaboration, Combination of searches for invisible Higgs boson decays with the ATLAS experiment, http://cds.cern.ch/record/2649407, 2018. (USA), the Tier-2 facilities worldwide and large non-WLCG resource [27] CMS Collaboration, Search for invisible decays of a Higgs boson produced providers. Major contributors of computing resources are listed in √ through vector boson fusion in proton-proton collisions at s = 13 TeV, arXiv: Ref. [90]. 1809.05937 [hep-ex], 2018. The ATLAS Collaboration / Physics Letters B 793 (2019) 499–519 507 [28] ATLAS Collaboration, Search for invisible decays of a Higgs boson using vector- [58] ATLAS Collaboration, E Tmiss performance in the ATLAS detector using 2015-2016 √ boson fusion in pp collisions at s = 8 TeV with the ATLAS detector, J. High LHC pp collisions, ATLAS-CONF-2018-023, http://cds.cern.ch/record/2625233, Energy Phys. 01 (2016) 172, arXiv:1508.07869 [hep-ex]. 2018. [29] CMS Collaboration, Searches for invisible decays of the Higgs boson in pp [59] ATLAS Collaboration, FastCaloSim performance plots, SIM-2018-001, http:// √ collisions at s = 7, 8, and 13 TeV, J. High Energy Phys. 02 (2017) 135, cern.ch/Atlas/GROUPS/PHYSICS/PLOTS/SIM-2018-001/, 2018. arXiv:1610.09218 [hep-ex]. [60] T. Gleisberg, et al., Event generation with SHERPA 1.1, J. High Energy Phys. 02 [30] ATLAS Collaboration, Constraints on new phenomena via Higgs boson couplings (2009) 007, arXiv:0811.4622 [hep-ph]. and invisible decays with the ATLAS detector, J. High Energy Phys. 11 (2015) [61] T. Gleisberg, S. Hoeche, Comix, a new matrix element generator, J. High Energy 206, arXiv:1509.00672 [hep-ex]. Phys. 12 (2008) 039, arXiv:0808.3674 [hep-ph]. [31] CMS Collaboration, Precise determination of the mass of the Higgs boson [62] F. Cascioli, P. Maierhofer, S. Pozzorini, Scattering amplitudes with open loops, and tests of compatibility of its couplings with the standard model predic- Phys. Rev. Lett. 108 (2012) 111601, arXiv:1111.5206 [hep-ph]. tions using proton collisions at 7 and 8 TeV, Eur. Phys. J. C 75 (2015) 212, [63] S. Schumann, F. Krauss, A parton shower algorithm based on Catani-Seymour arXiv:1412.8662 [hep-ex]. dipole factorisation, J. High Energy Phys. 03 (2008) 038, arXiv:0709.1027 [hep- [32] ATLAS and CMS Collaborations, Measurements of the Higgs boson production ph]. and decay rates and constraints on its couplings from a combined ATLAS and √ [64] S. Hoeche, F. Krauss, M. Schonherr, F. Siegert, QCD matrix elements + parton CMS analysis of the LHC pp collision data at s = 7 and 8 TeV, J. High Energy showers. The NLO case, J. High Energy Phys. 04 (2013) 027, arXiv:1207.5030 Phys. 08 (2016) 045, arXiv:1606.02266 [hep-ex]. [hep-ph]. [33] CMS Collaboration, Combined measurements of Higgs boson couplings in √ [65] J. Alwall, et al., The automated computation of tree-level and next-to-leading proton-proton collisions at s = 13 TeV, arXiv:1809.10733 [hep-ex], 2018. order differential cross sections, and their matching to parton shower simula- [34] ATLAS Collaboration, The ATLAS experiment at the CERN Large Hadron Collider, tions, J. High Energy Phys. 07 (2014) 079, arXiv:1405.0301 [hep-ph]. J. Instrum. 3 (2008) S08003. [66] D.J. Lange, The EvtGen particle decay simulation package, Nucl. Instrum. Meth- [35] ATLAS Collaboration, The ATLAS transverse-momentum trigger performance ods A 462 (2001) 152. at the LHC in 2011, ATLAS-CONF-2014-002, http://cds.cern.ch/record/1647616, [67] A.D. Martin, W.J. Stirling, R.S. Thorne, G. Watt, Parton distributions for the LHC, 2014. Eur. Phys. J. C 63 (2009) 189, arXiv:0901.0002 [hep-ph]. [36] ATLAS Collaboration, Analytical description of missing transverse-momentum trigger rates in ATLAS with 7 and 8 TeV data, ATL-DAQ-PUB-2017-002, http:// [68] ATLAS Collaboration, Summary of ATLAS Pythia 8 tunes, ATL-PHYS-PUB-2012- cds.cern.ch/record/2292378, 2017. 003, http://cds.cern.ch/record/1474107, 2011. [37] ATLAS TDAQ Collaboration, The ATLAS data acquisition and high level trigger [69] G. Cowan, K. Cranmer, E. Gross, O. Vitells, Asymptotic formulae for likelihood- system, J. Instrum. 11 (2016) P06008. based tests of new physics, Eur. Phys. J. C 71 (2011) 1554, Erratum: Eur. Phys. [38] ATLAS Collaboration, Topological cell clustering in the ATLAS calorimeters and J. C 73 (2013) 2501, arXiv:1007.1727 [physics.data-an]. its performance in LHC Run 1, Eur. Phys. J. C 77 (2017) 490, arXiv:1603.02934 [70] A.L. Read, Presentation of search results: the CL(s) technique, J. Phys. G 28 [hep-ex]. (2002) 2693. [39] ATLAS Collaboration, Performance of the ATLAS trigger system in 2015, Eur. [71] ATLAS Collaboration, Observation and measurement of Higgs boson decays to Phys. J. C 77 (2017) 317, arXiv:1611.09661 [hep-ex]. W W ∗ with the ATLAS detector, Phys. Rev. D 92 (2015) 012006, arXiv:1412. [40] ATLAS Collaboration, Trigger menu in 2016, ATL-DAQ-PUB-2017-001, http://cds. 2641 [hep-ex]. cern.ch/record/2242069, 2017. [72] ATLAS Collaboration, Search for squarks and gluinos with the ATLAS detector [41] ATLAS Collaboration, Electron efficiency measurements with the ATLAS detec- in final states with jets and missing transverse momentum using 4.7 fb−1 of √ tor using 2012 LHC proton–proton collision data, Eur. Phys. J. C 77 (2017) 195, s = 7 TeV proton-proton collision data, Phys. Rev. D 87 (2013) 012008, arXiv: arXiv:1612.01456 [hep-ex]. 1208.0949 [hep-ex]. [42] ATLAS Collaboration, Electron efficiency measurements with the ATLAS detec- [73] CMS Collaboration, Search for new physics in the multijet and missing trans- √ tor using the 2015 LHC proton-proton collision data, ATLAS-CONF-2016-024, verse momentum final state in proton-proton collisions at s = 8 TeV, J. High http://cds.cern.ch/record/2157687, 2016. Energy Phys. 06 (2014) 055, arXiv:1402.4770 [hep-ex]. [43] ATLAS Collaboration, Muon reconstruction performance of the ATLAS detector [74] CMS Collaboration, Search for new physics with jets and missing transverse √ √ in proton–proton collision data at s = 13 TeV, Eur. Phys. J. C 76 (2016) 292, momentum in pp collisions at s = 7 TeV, J. High Energy Phys. 08 (2011) 155, arXiv:1603.05598 [hep-ex]. arXiv:1106.4503 [hep-ex]. [44] M. Cacciari, G.P. Salam, G. Soyez, Anti-kt jet clustering algorithm, J. High Energy [75] ATLAS Collaboration, Jet energy scale measurements and their systematic un- √ Phys. 04 (2008) 063, arXiv:0802.1189 [hep-ex]. certainties in proton-proton collisions at s = 13 TeV with the ATLAS detector, [45] ATLAS Collaboration, Performance of pile-up mitigation techniques for jets in Phys. Rev. D 96 (2017) 072002, arXiv:1703.09665 [hep-ex]. √ pp collisions at s = 8 TeV using the ATLAS detector, Eur. Phys. J. C 76 (2016) [76] ATLAS Collaboration, Performance of missing transverse momentum recon- √ 581, arXiv:1510.03823 [hep-ex]. struction with the ATLAS detector using proton-proton collisions at s = 13 [46] ATLAS Collaboration, Selection of jets produced in 13 TeV proton-proton TeV, arXiv:1802.08168 [hep-ex], 2018. collisions with the ATLAS detector, ATLAS-CONF-2015-029, http://cds.cern.ch/ √ [77] ATLAS Collaboration, Luminosity determination in pp collisions at s = 8 TeV record/2037702, 2015. using the ATLAS detector at the LHC, Eur. Phys. J. C 76 (2016) 653, arXiv:1608. [47] ATLAS Collaboration, Search for squarks and gluinos in final states with 03953 [hep-ex]. hadronically decaying τ -leptons, jets, and missing transverse momentum us- √ [78] G. Avoni, et al., The new LUCID-2 detector for luminosity measurement and ing pp collisions at s = 13 TeV with the ATLAS detector, Phys. Rev. D 99 monitoring in ATLAS, J. Instrum. 13 (2018) P07017. (2019) 012009, arXiv:1808.06358 [hep-ex]. [79] E. Bothmann, M. Schönherr, S. Schumann, Reweighting QCD matrix-element [48] ATLAS Collaboration, The ATLAS simulation infrastructure, Eur. Phys. J. C 70 and parton-shower calculations, Eur. Phys. J. C 76 (2016) 590, arXiv:1606.08753 (2010) 823, arXiv:1005.4568 [physics.ins-det]. [hep-ph]. [49] GEANT4 Collaboration, GEANT4—a simulation toolkit, Nucl. Instrum. Methods [80] S. Dittmaier, C. Mariotti, G. Passarino, S. Heinemeyer, R. Tanaka (Eds.), Hand- A 506 (2003) 250. book of LHC Higgs Cross Sections: 3. Higgs Properties, 2013, Tech. Rep. CERN- [50] P. Nason, C. Oleari, NLO Higgs boson production via vector-boson fusion 2013-004, FERMILAB-CONF-13-667-T, arXiv:1307.1347 [hep-ph], 2013. matched with shower in POWHEG [POWHEG-BOX r1655], J. High Energy Phys. [81] I.W. Stewart, F.J. Tackmann, Theory uncertainties for Higgs and other searches 02 (2010) 037, arXiv:0911.5299 [hep-ph]. using jet bins, Phys. Rev. D 85 (2012) 034011, arXiv:1107.2117 [hep-ph]. [51] M. Ciccolini, A. Denner, S. Dittmaier, Electroweak and QCD corrections to Higgs [82] B. Patt, F. Wilczek, Higgs-field portal into hidden sectors, MIT-CTP-3745, arXiv: production via vector-boson fusion at the LHC, Phys. Rev. D 77 (2003) 013002, hep-ph/0605188, 2006. arXiv:0710.4749 [hep-ex]. [52] T. Sjöstrand, S. Mrenna, P.Z. Skands, A brief introduction to PYTHIA 8.1, Comput. [83] P.J. Fox, R. Harnik, J. Kopp, Y. Tsai, Missing energy signatures of dark matter at Phys. Commun. 178 (2008) 852, arXiv:0710.3820 [hep-ph]. the LHC, Phys. Rev. D 85 (2012) 056011, arXiv:1109.4398 [hep-ph]. [53] ATLAS Collaboration, Measurement of the Z /γ ∗ boson transverse momentum [84] A. De Simone, G.F. Giudice, A. Strumia, Benchmarks for dark matter searches at √ the LHC, J. High Energy Phys. 06 (2014) 081, arXiv:1402.6287 [hep-ph]. distribution in pp collisions at s = 7 TeV with the ATLAS detector, J. High Energy Phys. 09 (2014) 145, arXiv:1406.3660 [hep-ex]. [85] D.S. Akerib, et al., Results from a search for dark matter in the complete LUX [54] R.D. Ball, et al., Parton distributions for the LHC Run II, J. High Energy Phys. 04 exposure, Phys. Rev. Lett. 118 (2017) 021303, arXiv:1608.07648 [astro-ph.CO]. (2015) 040, arXiv:1410.8849 [hep-ph]. [86] X. Cui, et al., Dark matter results from 54-ton-day exposure of PandaX-II ex- [55] K. Hamilton, P. Nason, E. Re, G. Zanderighi, NNLOPS simulation of Higgs boson periment, Phys. Rev. Lett. 119 (2017) 181302, arXiv:1708.06917 [astro-ph.CO]. production, J. High Energy Phys. 10 (2013) 222, arXiv:1309.0017 [hep-ph]. [87] E. Aprile, et al., Dark matter search results from a one tonne×year exposure of [56] J. Butterworth, et al., PDF4LHC recommendations for LHC Run II, J. Phys. G 43 XENON1T, arXiv:1805.12562 [astro-ph.CO], 2018. (2016) 023001, arXiv:1510.03865 [hep-ph]. [88] M. Hoferichter, P. Klos, J. Menéndez, A. Schwenk, Improved limits for Higgs- [57] W. Lukas, Fast simulation for ATLAS: Atlfast-II and ISF, J. Phys. Conf. Ser. 396 portal dark matter from LHC searches, Phys. Rev. Lett. 119 (2017) 181803, (2012) 022031. arXiv:1708.02245 [hep-ph]. 508 The ATLAS Collaboration / Physics Letters B 793 (2019) 499–519 [89] S. Baek, P. Ko, W.-I. Park, Invisible Higgs decay width versus dark matter direct [90] ATLAS Collaboration, ATLAS Computing Acknowledgements ATL-GEN-PUB- detection cross section in Higgs portal dark matter models, Phys. Rev. D 90 2016–002, http://cds.cern.ch/record/2202407, 2016. (2014) 055014, arXiv:1405.3530 [hep-ph]. The ATLAS Collaboration M. Aaboud 34d , G. Aad 99 , B. Abbott 125 , O. Abdinov 13,∗ , B. Abeloos 129 , D.K. Abhayasinghe 91 , S.H. Abidi 164 , O.S. AbouZeid 39 , N.L. Abraham 153 , H. Abramowicz 158 , H. Abreu 157 , Y. Abulaiti 6 , B.S. Acharya 64a,64b,o , S. Adachi 160 , L. Adamczyk 81a , J. Adelman 119 , M. Adersberger 112 , A. Adiguzel 12c,ah , T. Adye 141 , A.A. Affolder 143 , Y. Afik 157 , C. Agheorghiesei 27c , J.A. Aguilar-Saavedra 137f,137a , F. Ahmadov 77,af , G. Aielli 71a,71b , S. Akatsuka 83 , T.P.A. Åkesson 94 , E. Akilli 52 , A.V. Akimov 108 , G.L. Alberghi 23b,23a , J. Albert 173 , P. Albicocco 49 , M.J. Alconada Verzini 86 , S. Alderweireldt 117 , M. Aleksa 35 , I.N. Aleksandrov 77 , C. Alexa 27b , T. Alexopoulos 10 , M. Alhroob 125 , B. Ali 139 , G. Alimonti 66a , J. Alison 36 , S.P. Alkire 145 , C. Allaire 129 , B.M.M. Allbrooke 153 , B.W. Allen 128 , P.P. Allport 21 , A. Aloisio 67a,67b , A. Alonso 39 , F. Alonso 86 , C. Alpigiani 145 , A.A. Alshehri 55 , M.I. Alstaty 99 , B. Alvarez Gonzalez 35 , D. Álvarez Piqueras 171 , M.G. Alviggi 67a,67b , B.T. Amadio 18 , Y. Amaral Coutinho 78b , L. Ambroz 132 , C. Amelung 26 , D. Amidei 103 , S.P. Amor Dos Santos 137a,137c , S. Amoroso 44 , C.S. Amrouche 52 , C. Anastopoulos 146 , L.S. Ancu 52 , N. Andari 21 , T. Andeen 11 , C.F. Anders 59b , J.K. Anders 20 , K.J. Anderson 36 , A. Andreazza 66a,66b , V. Andrei 59a , C.R. Anelli 173 , S. Angelidakis 37 , I. Angelozzi 118 , A. Angerami 38 , A.V. Anisenkov 120b,120a , A. Annovi 69a , C. Antel 59a , M.T. Anthony 146 , M. Antonelli 49 , D.J.A. Antrim 168 , F. Anulli 70a , M. Aoki 79 , L. Aperio Bella 35 , G. Arabidze 104 , J.P. Araque 137a , V. Araujo Ferraz 78b , R. Araujo Pereira 78b , A.T.H. Arce 47 , R.E. Ardell 91 , F.A. Arduh 86 , J-F. Arguin 107 , S. Argyropoulos 75 , A.J. Armbruster 35 , L.J. Armitage 90 , A Armstrong 168 , O. Arnaez 164 , H. Arnold 118 , M. Arratia 31 , O. Arslan 24 , A. Artamonov 109,∗ , G. Artoni 132 , S. Artz 97 , S. Asai 160 , N. Asbah 44 , A. Ashkenazi 158 , E.M. Asimakopoulou 169 , L. Asquith 153 , K. Assamagan 29 , R. Astalos 28a , R.J. Atkin 32a , M. Atkinson 170 , N.B. Atlay 148 , K. Augsten 139 , G. Avolio 35 , R. Avramidou 58a , M.K. Ayoub 15a , G. Azuelos 107,au , A.E. Baas 59a , M.J. Baca 21 , H. Bachacou 142 , K. Bachas 65a,65b , M. Backes 132 , P. Bagnaia 70a,70b , M. Bahmani 82 , H. Bahrasemani 149 , A.J. Bailey 171 , J.T. Baines 141 , M. Bajic 39 , C. Bakalis 10 , O.K. Baker 180 , P.J. Bakker 118 , D. Bakshi Gupta 93 , E.M. Baldin 120b,120a , P. Balek 177 , F. Balli 142 , W.K. Balunas 134 , J. Balz 97 , E. Banas 82 , A. Bandyopadhyay 24 , S. Banerjee 178,k , A.A.E. Bannoura 179 , L. Barak 158 , W.M. Barbe 37 , E.L. Barberio 102 , D. Barberis 53b,53a , M. Barbero 99 , T. Barillari 113 , M-S. Barisits 35 , J. Barkeloo 128 , T. Barklow 150 , N. Barlow 31 , R. Barnea 157 , S.L. Barnes 58c , B.M. Barnett 141 , R.M. Barnett 18 , Z. Barnovska-Blenessy 58a , A. Baroncelli 72a , G. Barone 26 , A.J. Barr 132 , L. Barranco Navarro 171 , F. Barreiro 96 , J. Barreiro Guimarães da Costa 15a , R. Bartoldus 150 , A.E. Barton 87 , P. Bartos 28a , A. Basalaev 135 , A. Bassalat 129 , R.L. Bates 55 , S.J. Batista 164 , S. Batlamous 34e , J.R. Batley 31 , M. Battaglia 143 , M. Bauce 70a,70b , F. Bauer 142 , K.T. Bauer 168 , H.S. Bawa 150,m , J.B. Beacham 123 , M.D. Beattie 87 , T. Beau 133 , P.H. Beauchemin 167 , P. Bechtle 24 , H.C. Beck 51 , H.P. Beck 20,r , K. Becker 50 , M. Becker 97 , C. Becot 44 , A. Beddall 12d , A.J. Beddall 12a , V.A. Bednyakov 77 , M. Bedognetti 118 , C.P. Bee 152 , T.A. Beermann 35 , M. Begalli 78b , M. Begel 29 , A. Behera 152 , J.K. Behr 44 , A.S. Bell 92 , G. Bella 158 , L. Bellagamba 23b , A. Bellerive 33 , M. Bellomo 157 , P. Bellos 9 , K. Belotskiy 110 , N.L. Belyaev 110 , O. Benary 158,∗ , D. Benchekroun 34a , M. Bender 112 , N. Benekos 10 , Y. Benhammou 158 , E. Benhar Noccioli 180 , J. Benitez 75 , D.P. Benjamin 47 , M. Benoit 52 , J.R. Bensinger 26 , S. Bentvelsen 118 , L. Beresford 132 , M. Beretta 49 , D. Berge 44 , E. Bergeaas Kuutmann 169 , N. Berger 5 , L.J. Bergsten 26 , J. Beringer 18 , S. Berlendis 7 , N.R. Bernard 100 , G. Bernardi 133 , C. Bernius 150 , F.U. Bernlochner 24 , T. Berry 91 , P. Berta 97 , C. Bertella 15a , G. Bertoli 43a,43b , I.A. Bertram 87 , G.J. Besjes 39 , O. Bessidskaia Bylund 43a,43b , M. Bessner 44 , N. Besson 142 , A. Bethani 98 , S. Bethke 113 , A. Betti 24 , A.J. Bevan 90 , J. Beyer 113 , R.M. Bianchi 136 , O. Biebel 112 , D. Biedermann 19 , R. Bielski 98 , K. Bierwagen 97 , N.V. Biesuz 69a,69b , M. Biglietti 72a , T.R.V. Billoud 107 , M. Bindi 51 , A. Bingul 12d , C. Bini 70a,70b , S. Biondi 23b,23a , M. Birman 177 , T. Bisanz 51 , J.P. Biswal 158 , C. Bittrich 46 , D.M. Bjergaard 47 , J.E. Black 150 , K.M. Black 25 , T. Blazek 28a , I. Bloch 44 , C. Blocker 26 , A. Blue 55 , U. Blumenschein 90 , Dr. Blunier 144a , G.J. Bobbink 118 , V.S. Bobrovnikov 120b,120a , S.S. Bocchetta 94 , A. Bocci 47 , D. Boerner 179 , D. Bogavac 112 , A.G. Bogdanchikov 120b,120a , C. Bohm 43a , V. Boisvert 91 , P. Bokan 169 , T. Bold 81a , A.S. Boldyrev 111 , A.E. Bolz 59b , M. Bomben 133 , M. Bona 90 , J.S. Bonilla 128 , M. Boonekamp 142 , A. Borisov 121 , G. Borissov 87 , J. Bortfeldt 35 , D. Bortoletto 132 , V. Bortolotto 71a,61b,61c,71b , D. Boscherini 23b , M. Bosman 14 , J.D. Bossio Sola 30 , K. Bouaouda 34a , J. Boudreau 136 , E.V. Bouhova-Thacker 87 , D. Boumediene 37 , The ATLAS Collaboration / Physics Letters B 793 (2019) 499–519 509 C. Bourdarios 129 , S.K. Boutle 55 , A. Boveia 123 , J. Boyd 35 , I.R. Boyko 77 , A.J. Bozson 91 , J. Bracinik 21 , N. Brahimi 99 , A. Brandt 8 , G. Brandt 179 , O. Brandt 59a , F. Braren 44 , U. Bratzler 161 , B. Brau 100 , J.E. Brau 128 , W.D. Breaden Madden 55 , K. Brendlinger 44 , A.J. Brennan 102 , L. Brenner 44 , R. Brenner 169 , S. Bressler 177 , B. Brickwedde 97 , D.L. Briglin 21 , D. Britton 55 , D. Britzger 59b , I. Brock 24 , R. Brock 104 , G. Brooijmans 38 , T. Brooks 91 , W.K. Brooks 144b , E. Brost 119 , J.H Broughton 21 , P.A. Bruckman de Renstrom 82 , D. Bruncko 28b , A. Bruni 23b , G. Bruni 23b , L.S. Bruni 118 , S. Bruno 71a,71b , B.H. Brunt 31 , M. Bruschi 23b , N. Bruscino 136 , P. Bryant 36 , L. Bryngemark 44 , T. Buanes 17 , Q. Buat 35 , P. Buchholz 148 , A.G. Buckley 55 , I.A. Budagov 77 , M.K. Bugge 131 , F. Bührer 50 , O. Bulekov 110 , D. Bullock 8 , T.J. Burch 119 , S. Burdin 88 , C.D. Burgard 118 , A.M. Burger 5 , B. Burghgrave 119 , K. Burka 82 , S. Burke 141 , I. Burmeister 45 , J.T.P. Burr 132 , D. Büscher 50 , V. Büscher 97 , E. Buschmann 51 , P. Bussey 55 , J.M. Butler 25 , C.M. Buttar 55 , J.M. Butterworth 92 , P. Butti 35 , W. Buttinger 35 , A. Buzatu 155 , A.R. Buzykaev 120b,120a , G. Cabras 23b,23a , S. Cabrera Urbán 171 , D. Caforio 139 , H. Cai 170 , V.M.M. Cairo 2 , O. Cakir 4a , N. Calace 52 , P. Calafiura 18 , A. Calandri 99 , G. Calderini 133 , P. Calfayan 63 , G. Callea 40b,40a , L.P. Caloba 78b , S. Calvente Lopez 96 , D. Calvet 37 , S. Calvet 37 , T.P. Calvet 152 , M. Calvetti 69a,69b , R. Camacho Toro 133 , S. Camarda 35 , P. Camarri 71a,71b , D. Cameron 131 , R. Caminal Armadans 100 , C. Camincher 35 , S. Campana 35 , M. Campanelli 92 , A. Camplani 39 , A. Campoverde 148 , V. Canale 67a,67b , M. Cano Bret 58c , J. Cantero 126 , T. Cao 158 , Y. Cao 170 , M.D.M. Capeans Garrido 35 , I. Caprini 27b , M. Caprini 27b , M. Capua 40b,40a , R.M. Carbone 38 , R. Cardarelli 71a , F.C. Cardillo 50 , I. Carli 140 , T. Carli 35 , G. Carlino 67a , B.T. Carlson 136 , L. Carminati 66a,66b , R.M.D. Carney 43a,43b , S. Caron 117 , E. Carquin 144b , S. Carrá 66a,66b , G.D. Carrillo-Montoya 35 , D. Casadei 32b , M.P. Casado 14,g , A.F. Casha 164 , M. Casolino 14 , D.W. Casper 168 , R. Castelijn 118 , F.L. Castillo 171 , V. Castillo Gimenez 171 , N.F. Castro 137a,137e , A. Catinaccio 35 , J.R. Catmore 131 , A. Cattai 35 , J. Caudron 24 , V. Cavaliere 29 , E. Cavallaro 14 , D. Cavalli 66a , M. Cavalli-Sforza 14 , V. Cavasinni 69a,69b , E. Celebi 12b , F. Ceradini 72a,72b , L. Cerda Alberich 171 , A.S. Cerqueira 78a , A. Cerri 153 , L. Cerrito 71a,71b , F. Cerutti 18 , A. Cervelli 23b,23a , S.A. Cetin 12b , A. Chafaq 34a , D Chakraborty 119 , S.K. Chan 57 , W.S. Chan 118 , Y.L. Chan 61a , J.D. Chapman 31 , D.G. Charlton 21 , C.C. Chau 33 , C.A. Chavez Barajas 153 , S. Che 123 , A. Chegwidden 104 , S. Chekanov 6 , S.V. Chekulaev 165a , G.A. Chelkov 77,at , M.A. Chelstowska 35 , C. Chen 58a , C.H. Chen 76 , H. Chen 29 , J. Chen 58a , J. Chen 38 , S. Chen 134 , S.J. Chen 15c , X. Chen 15b,as , Y. Chen 80 , Y-H. Chen 44 , H.C. Cheng 103 , H.J. Cheng 15d , A. Cheplakov 77 , E. Cheremushkina 121 , R. Cherkaoui El Moursli 34e , E. Cheu 7 , K. Cheung 62 , L. Chevalier 142 , V. Chiarella 49 , G. Chiarelli 69a , G. Chiodini 65a , A.S. Chisholm 35 , A. Chitan 27b , I. Chiu 160 , Y.H. Chiu 173 , M.V. Chizhov 77 , K. Choi 63 , A.R. Chomont 129 , S. Chouridou 159 , Y.S. Chow 118 , V. Christodoulou 92 , M.C. Chu 61a , J. Chudoba 138 , A.J. Chuinard 101 , J.J. Chwastowski 82 , L. Chytka 127 , D. Cinca 45 , V. Cindro 89 , I.A. Cioară 24 , A. Ciocio 18 , F. Cirotto 67a,67b , Z.H. Citron 177 , M. Citterio 66a , A. Clark 52 , M.R. Clark 38 , P.J. Clark 48 , C. Clement 43a,43b , Y. Coadou 99 , M. Cobal 64a,64c , A. Coccaro 53b,53a , J. Cochran 76 , A.E.C. Coimbra 177 , L. Colasurdo 117 , B. Cole 38 , A.P. Colijn 118 , J. Collot 56 , P. Conde Muiño 137a,137b , E. Coniavitis 50 , S.H. Connell 32b , I.A. Connelly 98 , S. Constantinescu 27b , F. Conventi 67a,av , A.M. Cooper-Sarkar 132 , F. Cormier 172 , K.J.R. Cormier 164 , M. Corradi 70a,70b , E.E. Corrigan 94 , F. Corriveau 101,ad , A. Cortes-Gonzalez 35 , M.J. Costa 171 , D. Costanzo 146 , G. Cottin 31 , G. Cowan 91 , B.E. Cox 98 , J. Crane 98 , K. Cranmer 122 , S.J. Crawley 55 , R.A. Creager 134 , G. Cree 33 , S. Crépé-Renaudin 56 , F. Crescioli 133 , M. Cristinziani 24 , V. Croft 122 , G. Crosetti 40b,40a , A. Cueto 96 , T. Cuhadar Donszelmann 146 , A.R. Cukierman 150 , J. Cúth 97 , S. Czekierda 82 , P. Czodrowski 35 , M.J. Da Cunha Sargedas De Sousa 58b , C. Da Via 98 , W. Dabrowski 81a , T. Dado 28a,y , S. Dahbi 34e , T. Dai 103 , F. Dallaire 107 , C. Dallapiccola 100 , M. Dam 39 , G. D’amen 23b,23a , J. Damp 97 , J.R. Dandoy 134 , M.F. Daneri 30 , N.P. Dang 178,k , N.D Dann 98 , M. Danninger 172 , V. Dao 35 , G. Darbo 53b , S. Darmora 8 , O. Dartsi 5 , A. Dattagupta 128 , T. Daubney 44 , S. D’Auria 55 , W. Davey 24 , C. David 44 , T. Davidek 140 , D.R. Davis 47 , E. Dawe 102 , I. Dawson 146 , K. De 8 , R. De Asmundis 67a , A. De Benedetti 125 , M. De Beurs 118 , S. De Castro 23b,23a , S. De Cecco 70a,70b , N. De Groot 117 , P. de Jong 118 , H. De la Torre 104 , F. De Lorenzi 76 , A. De Maria 51,t , D. De Pedis 70a , A. De Salvo 70a , U. De Sanctis 71a,71b , A. De Santo 153 , K. De Vasconcelos Corga 99 , J.B. De Vivie De Regie 129 , C. Debenedetti 143 , D.V. Dedovich 77 , N. Dehghanian 3 , M. Del Gaudio 40b,40a , J. Del Peso 96 , Y. Delabat Diaz 44 , D. Delgove 129 , F. Deliot 142 , C.M. Delitzsch 7 , M. Della Pietra 67a,67b , D. Della Volpe 52 , A. Dell’Acqua 35 , L. Dell’Asta 25 , M. Delmastro 5 , C. Delporte 129 , P.A. Delsart 56 , D.A. DeMarco 164 , S. Demers 180 , M. Demichev 77 , S.P. Denisov 121 , D. Denysiuk 118 , L. D’Eramo 133 , D. Derendarz 82 , J.E. Derkaoui 34d , F. Derue 133 , P. Dervan 88 , K. Desch 24 , 510 The ATLAS Collaboration / Physics Letters B 793 (2019) 499–519 C. Deterre 44 , K. Dette 164 , M.R. Devesa 30 , P.O. Deviveiros 35 , A. Dewhurst 141 , S. Dhaliwal 26 , F.A. Di Bello 52 , A. Di Ciaccio 71a,71b , L. Di Ciaccio 5 , W.K. Di Clemente 134 , C. Di Donato 67a,67b , A. Di Girolamo 35 , B. Di Micco 72a,72b , R. Di Nardo 100 , K.F. Di Petrillo 57 , A. Di Simone 50 , R. Di Sipio 164 , D. Di Valentino 33 , C. Diaconu 99 , M. Diamond 164 , F.A. Dias 39 , T. Dias Do Vale 137a , M.A. Diaz 144a , J. Dickinson 18 , E.B. Diehl 103 , J. Dietrich 19 , S. Díez Cornell 44 , A. Dimitrievska 18 , J. Dingfelder 24 , F. Dittus 35 , F. Djama 99 , T. Djobava 156b , J.I. Djuvsland 59a , M.A.B. Do Vale 78c , M. Dobre 27b , D. Dodsworth 26 , C. Doglioni 94 , J. Dolejsi 140 , Z. Dolezal 140 , M. Donadelli 78d , J. Donini 37 , A. D’onofrio 90 , M. D’Onofrio 88 , J. Dopke 141 , A. Doria 67a , M.T. Dova 86 , A.T. Doyle 55 , E. Drechsler 51 , E. Dreyer 149 , T. Dreyer 51 , Y. Du 58b , J. Duarte-Campderros 158 , F. Dubinin 108 , M. Dubovsky 28a , A. Dubreuil 52 , E. Duchovni 177 , G. Duckeck 112 , A. Ducourthial 133 , O.A. Ducu 107,x , D. Duda 113 , A. Dudarev 35 , A.C. Dudder 97 , E.M. Duffield 18 , L. Duflot 129 , M. Dührssen 35 , C. Dülsen 179 , M. Dumancic 177 , A.E. Dumitriu 27b,e , A.K. Duncan 55 , M. Dunford 59a , A. Duperrin 99 , H. Duran Yildiz 4a , M. Düren 54 , A. Durglishvili 156b , D. Duschinger 46 , B. Dutta 44 , D. Duvnjak 1 , M. Dyndal 44 , S. Dysch 98 , B.S. Dziedzic 82 , C. Eckardt 44 , K.M. Ecker 113 , R.C. Edgar 103 , T. Eifert 35 , G. Eigen 17 , K. Einsweiler 18 , T. Ekelof 169 , M. El Kacimi 34c , R. El Kosseifi 99 , V. Ellajosyula 99 , M. Ellert 169 , F. Ellinghaus 179 , A.A. Elliot 90 , N. Ellis 35 , J. Elmsheuser 29 , M. Elsing 35 , D. Emeliyanov 141 , Y. Enari 160 , J.S. Ennis 175 , M.B. Epland 47 , J. Erdmann 45 , A. Ereditato 20 , S. Errede 170 , M. Escalier 129 , C. Escobar 171 , O. Estrada Pastor 171 , A.I. Etienvre 142 , E. Etzion 158 , H. Evans 63 , A. Ezhilov 135 , M. Ezzi 34e , F. Fabbri 55 , L. Fabbri 23b,23a , V. Fabiani 117 , G. Facini 92 , R.M. Faisca Rodrigues Pereira 137a , R.M. Fakhrutdinov 121 , S. Falciano 70a , P.J. Falke 5 , S. Falke 5 , J. Faltova 140 , Y. Fang 15a , M. Fanti 66a,66b , A. Farbin 8 , A. Farilla 72a , E.M. Farina 68a,68b , T. Farooque 104 , S. Farrell 18 , S.M. Farrington 175 , P. Farthouat 35 , F. Fassi 34e , P. Fassnacht 35 , D. Fassouliotis 9 , M. Faucci Giannelli 48 , A. Favareto 53b,53a , W.J. Fawcett 52 , L. Fayard 129 , O.L. Fedin 135,p , W. Fedorko 172 , M. Feickert 41 , S. Feigl 131 , L. Feligioni 99 , C. Feng 58b , E.J. Feng 35 , M. Feng 47 , M.J. Fenton 55 , A.B. Fenyuk 121 , L. Feremenga 8 , J. Ferrando 44 , A. Ferrari 169 , P. Ferrari 118 , R. Ferrari 68a , D.E. Ferreira de Lima 59b , A. Ferrer 171 , D. Ferrere 52 , C. Ferretti 103 , F. Fiedler 97 , A. Filipčič 89 , F. Filthaut 117 , K.D. Finelli 25 , M.C.N. Fiolhais 137a,137c,a , L. Fiorini 171 , C. Fischer 14 , W.C. Fisher 104 , N. Flaschel 44 , I. Fleck 148 , P. Fleischmann 103 , R.R.M. Fletcher 134 , T. Flick 179 , B.M. Flierl 112 , L.M. Flores 134 , L.R. Flores Castillo 61a , N. Fomin 17 , G.T. Forcolin 98 , A. Formica 142 , F.A. Förster 14 , A.C. Forti 98 , A.G. Foster 21 , D. Fournier 129 , H. Fox 87 , S. Fracchia 146 , P. Francavilla 69a,69b , M. Franchini 23b,23a , S. Franchino 59a , D. Francis 35 , L. Franconi 131 , M. Franklin 57 , M. Frate 168 , M. Fraternali 68a,68b , D. Freeborn 92 , S.M. Fressard-Batraneanu 35 , B. Freund 107 , W.S. Freund 78b , D. Froidevaux 35 , J.A. Frost 132 , C. Fukunaga 161 , E. Fullana Torregrosa 171 , T. Fusayasu 114 , J. Fuster 171 , O. Gabizon 157 , A. Gabrielli 23b,23a , A. Gabrielli 18 , G.P. Gach 81a , S. Gadatsch 52 , P. Gadow 113 , G. Gagliardi 53b,53a , L.G. Gagnon 107 , C. Galea 27b , B. Galhardo 137a,137c , E.J. Gallas 132 , B.J. Gallop 141 , P. Gallus 139 , G. Galster 39 , R. Gamboa Goni 90 , K.K. Gan 123 , S. Ganguly 177 , Y. Gao 88 , Y.S. Gao 150,m , C. García 171 , J.E. García Navarro 171 , J.A. García Pascual 15a , M. Garcia-Sciveres 18 , R.W. Gardner 36 , N. Garelli 150 , V. Garonne 131 , K. Gasnikova 44 , A. Gaudiello 53b,53a , G. Gaudio 68a , I.L. Gavrilenko 108 , A. Gavrilyuk 109 , C. Gay 172 , G. Gaycken 24 , E.N. Gazis 10 , C.N.P. Gee 141 , J. Geisen 51 , M. Geisen 97 , M.P. Geisler 59a , K. Gellerstedt 43a,43b , C. Gemme 53b , M.H. Genest 56 , C. Geng 103 , S. Gentile 70a,70b , C. Gentsos 159 , S. George 91 , D. Gerbaudo 14 , G. Gessner 45 , S. Ghasemi 148 , M. Ghasemi Bostanabad 173 , M. Ghneimat 24 , B. Giacobbe 23b , S. Giagu 70a,70b , N. Giangiacomi 23b,23a , P. Giannetti 69a , A. Giannini 67a,67b , S.M. Gibson 91 , M. Gignac 143 , D. Gillberg 33 , G. Gilles 179 , D.M. Gingrich 3,au , M.P. Giordani 64a,64c , F.M. Giorgi 23b , P.F. Giraud 142 , P. Giromini 57 , G. Giugliarelli 64a,64c , D. Giugni 66a , F. Giuli 132 , M. Giulini 59b , S. Gkaitatzis 159 , I. Gkialas 9,j , E.L. Gkougkousis 14 , P. Gkountoumis 10 , L.K. Gladilin 111 , C. Glasman 96 , J. Glatzer 14 , P.C.F. Glaysher 44 , A. Glazov 44 , M. Goblirsch-Kolb 26 , J. Godlewski 82 , S. Goldfarb 102 , T. Golling 52 , D. Golubkov 121 , A. Gomes 137a,137b,137d , R. Goncalves Gama 78a , R. Gonçalo 137a , G. Gonella 50 , L. Gonella 21 , A. Gongadze 77 , F. Gonnella 21 , J.L. Gonski 57 , S. González de la Hoz 171 , S. Gonzalez-Sevilla 52 , L. Goossens 35 , P.A. Gorbounov 109 , H.A. Gordon 29 , B. Gorini 35 , E. Gorini 65a,65b , A. Gorišek 89 , A.T. Goshaw 47 , C. Gössling 45 , M.I. Gostkin 77 , C.A. Gottardo 24 , C.R. Goudet 129 , D. Goujdami 34c , A.G. Goussiou 145 , N. Govender 32b,c , C. Goy 5 , E. Gozani 157 , I. Grabowska-Bold 81a , P.O.J. Gradin 169 , E.C. Graham 88 , J. Gramling 168 , E. Gramstad 131 , S. Grancagnolo 19 , V. Gratchev 135 , P.M. Gravila 27f , C. Gray 55 , H.M. Gray 18 , Z.D. Greenwood 93,aj , C. Grefe 24 , K. Gregersen 92 , I.M. Gregor 44 , P. Grenier 150 , K. Grevtsov 44 , J. Griffiths 8 , A.A. Grillo 143 , K. Grimm 150,b , S. Grinstein 14,z , Ph. Gris 37 , J.-F. Grivaz 129 , The ATLAS Collaboration / Physics Letters B 793 (2019) 499–519 511 S. Groh 97 , E. Gross 177 , J. Grosse-Knetter 51 , G.C. Grossi 93 , Z.J. Grout 92 , C. Grud 103 , A. Grummer 116 , L. Guan 103 , W. Guan 178 , J. Guenther 35 , A. Guerguichon 129 , F. Guescini 165a , D. Guest 168 , R. Gugel 50 , B. Gui 123 , T. Guillemin 5 , S. Guindon 35 , U. Gul 55 , C. Gumpert 35 , J. Guo 58c , W. Guo 103 , Y. Guo 58a,s , Z. Guo 99 , R. Gupta 41 , S. Gurbuz 12c , G. Gustavino 125 , B.J. Gutelman 157 , P. Gutierrez 125 , C. Gutschow 92 , C. Guyot 142 , M.P. Guzik 81a , C. Gwenlan 132 , C.B. Gwilliam 88 , A. Haas 122 , C. Haber 18 , H.K. Hadavand 8 , N. Haddad 34e , A. Hadef 58a , S. Hageböck 24 , M. Hagihara 166 , H. Hakobyan 181,∗ , M. Haleem 174 , J. Haley 126 , G. Halladjian 104 , G.D. Hallewell 99 , K. Hamacher 179 , P. Hamal 127 , K. Hamano 173 , A. Hamilton 32a , G.N. Hamity 146 , K. Han 58a,ai , L. Han 58a , S. Han 15d , K. Hanagaki 79,v , M. Hance 143 , D.M. Handl 112 , B. Haney 134 , R. Hankache 133 , P. Hanke 59a , E. Hansen 94 , J.B. Hansen 39 , J.D. Hansen 39 , M.C. Hansen 24 , P.H. Hansen 39 , K. Hara 166 , A.S. Hard 178 , T. Harenberg 179 , S. Harkusha 105 , P.F. Harrison 175 , N.M. Hartmann 112 , Y. Hasegawa 147 , A. Hasib 48 , S. Hassani 142 , S. Haug 20 , R. Hauser 104 , L. Hauswald 46 , L.B. Havener 38 , M. Havranek 139 , C.M. Hawkes 21 , R.J. Hawkings 35 , D. Hayden 104 , C. Hayes 152 , C.P. Hays 132 , J.M. Hays 90 , H.S. Hayward 88 , S.J. Haywood 141 , M.P. Heath 48 , V. Hedberg 94 , L. Heelan 8 , S. Heer 24 , K.K. Heidegger 50 , J. Heilman 33 , S. Heim 44 , T. Heim 18 , B. Heinemann 44,ap , J.J. Heinrich 112 , L. Heinrich 122 , C. Heinz 54 , J. Hejbal 138 , L. Helary 35 , A. Held 172 , S. Hellesund 131 , S. Hellman 43a,43b , C. Helsens 35 , R.C.W. Henderson 87 , Y. Heng 178 , S. Henkelmann 172 , A.M. Henriques Correia 35 , G.H. Herbert 19 , H. Herde 26 , V. Herget 174 , Y. Hernández Jiménez 32c , H. Herr 97 , M.G. Herrmann 112 , G. Herten 50 , R. Hertenberger 112 , L. Hervas 35 , T.C. Herwig 134 , G.G. Hesketh 92 , N.P. Hessey 165a , J.W. Hetherly 41 , S. Higashino 79 , E. Higón-Rodriguez 171 , K. Hildebrand 36 , E. Hill 173 , J.C. Hill 31 , K.K. Hill 29 , K.H. Hiller 44 , S.J. Hillier 21 , M. Hils 46 , I. Hinchliffe 18 , M. Hirose 130 , D. Hirschbuehl 179 , B. Hiti 89 , O. Hladik 138 , D.R. Hlaluku 32c , X. Hoad 48 , J. Hobbs 152 , N. Hod 165a , M.C. Hodgkinson 146 , A. Hoecker 35 , M.R. Hoeferkamp 116 , F. Hoenig 112 , D. Hohn 24 , D. Hohov 129 , T.R. Holmes 36 , M. Holzbock 112 , M. Homann 45 , S. Honda 166 , T. Honda 79 , T.M. Hong 136 , A. Hönle 113 , B.H. Hooberman 170 , W.H. Hopkins 128 , Y. Horii 115 , P. Horn 46 , A.J. Horton 149 , L.A. Horyn 36 , J-Y. Hostachy 56 , A. Hostiuc 145 , S. Hou 155 , A. Hoummada 34a , J. Howarth 98 , J. Hoya 86 , M. Hrabovsky 127 , J. Hrdinka 35 , I. Hristova 19 , J. Hrivnac 129 , A. Hrynevich 106 , T. Hryn’ova 5 , P.J. Hsu 62 , S.-C. Hsu 145 , Q. Hu 29 , S. Hu 58c , Y. Huang 15a , Z. Hubacek 139 , F. Hubaut 99 , M. Huebner 24 , F. Huegging 24 , T.B. Huffman 132 , E.W. Hughes 38 , M. Huhtinen 35 , R.F.H. Hunter 33 , P. Huo 152 , A.M. Hupe 33 , N. Huseynov 77,af , J. Huston 104 , J. Huth 57 , R. Hyneman 103 , G. Iacobucci 52 , G. Iakovidis 29 , I. Ibragimov 148 , L. Iconomidou-Fayard 129 , Z. Idrissi 34e , P. Iengo 35 , R. Ignazzi 39 , O. Igonkina 118,ab , R. Iguchi 160 , T. Iizawa 52 , Y. Ikegami 79 , M. Ikeno 79 , D. Iliadis 159 , N. Ilic 150 , F. Iltzsche 46 , G. Introzzi 68a,68b , M. Iodice 72a , K. Iordanidou 38 , V. Ippolito 70a,70b , M.F. Isacson 169 , N. Ishijima 130 , M. Ishino 160 , M. Ishitsuka 162 , W. Islam 126 , C. Issever 132 , S. Istin 12c,ao , F. Ito 166 , J.M. Iturbe Ponce 61a , R. Iuppa 73a,73b , A. Ivina 177 , H. Iwasaki 79 , J.M. Izen 42 , V. Izzo 67a , S. Jabbar 3 , P. Jacka 138 , P. Jackson 1 , R.M. Jacobs 24 , V. Jain 2 , G. Jäkel 179 , K.B. Jakobi 97 , K. Jakobs 50 , S. Jakobsen 74 , T. Jakoubek 138 , D.O. Jamin 126 , D.K. Jana 93 , R. Jansky 52 , J. Janssen 24 , M. Janus 51 , P.A. Janus 81a , G. Jarlskog 94 , N. Javadov 77,af , T. Javůrek 50 , M. Javurkova 50 , F. Jeanneau 142 , L. Jeanty 18 , J. Jejelava 156a,ag , A. Jelinskas 175 , P. Jenni 50,d , J. Jeong 44 , S. Jézéquel 5 , H. Ji 178 , J. Jia 152 , H. Jiang 76 , Y. Jiang 58a , Z. Jiang 150,q , S. Jiggins 50 , F.A. Jimenez Morales 37 , J. Jimenez Pena 171 , S. Jin 15c , A. Jinaru 27b , O. Jinnouchi 162 , H. Jivan 32c , P. Johansson 146 , K.A. Johns 7 , C.A. Johnson 63 , W.J. Johnson 145 , K. Jon-And 43a,43b , R.W.L. Jones 87 , S.D. Jones 153 , S. Jones 7 , T.J. Jones 88 , J. Jongmanns 59a , P.M. Jorge 137a,137b , J. Jovicevic 165a , X. Ju 178 , J.J. Junggeburth 113 , A. Juste Rozas 14,z , A. Kaczmarska 82 , M. Kado 129 , H. Kagan 123 , M. Kagan 150 , T. Kaji 176 , E. Kajomovitz 157 , C.W. Kalderon 94 , A. Kaluza 97 , S. Kama 41 , A. Kamenshchikov 121 , L. Kanjir 89 , Y. Kano 160 , V.A. Kantserov 110 , J. Kanzaki 79 , B. Kaplan 122 , L.S. Kaplan 178 , D. Kar 32c , M.J. Kareem 165b , E. Karentzos 10 , S.N. Karpov 77 , Z.M. Karpova 77 , V. Kartvelishvili 87 , A.N. Karyukhin 121 , K. Kasahara 166 , L. Kashif 178 , R.D. Kass 123 , A. Kastanas 151 , Y. Kataoka 160 , C. Kato 160 , J. Katzy 44 , K. Kawade 80 , K. Kawagoe 85 , T. Kawamoto 160 , G. Kawamura 51 , E.F. Kay 88 , V.F. Kazanin 120b,120a , R. Keeler 173 , R. Kehoe 41 , J.S. Keller 33 , E. Kellermann 94 , J.J. Kempster 21 , J. Kendrick 21 , O. Kepka 138 , S. Kersten 179 , B.P. Kerševan 89 , R.A. Keyes 101 , M. Khader 170 , F. Khalil-Zada 13 , A. Khanov 126 , A.G. Kharlamov 120b,120a , T. Kharlamova 120b,120a , A. Khodinov 163 , T.J. Khoo 52 , E. Khramov 77 , J. Khubua 156b , S. Kido 80 , M. Kiehn 52 , C.R. Kilby 91 , S.H. Kim 166 , Y.K. Kim 36 , N. Kimura 64a,64c , O.M. Kind 19 , B.T. King 88 , D. Kirchmeier 46 , J. Kirk 141 , A.E. Kiryunin 113 , T. Kishimoto 160 , D. Kisielewska 81a , V. Kitali 44 , O. Kivernyk 5 , E. Kladiva 28b,∗ , T. Klapdor-Kleingrothaus 50 , M.H. Klein 103 , 512 The ATLAS Collaboration / Physics Letters B 793 (2019) 499–519 M. Klein 88 , U. Klein 88 , K. Kleinknecht 97 , P. Klimek 119 , A. Klimentov 29 , R. Klingenberg 45,∗ , T. Klingl 24 , T. Klioutchnikova 35 , F.F. Klitzner 112 , P. Kluit 118 , S. Kluth 113 , E. Kneringer 74 , E.B.F.G. Knoops 99 , A. Knue 50 , A. Kobayashi 160 , D. Kobayashi 85 , T. Kobayashi 160 , M. Kobel 46 , M. Kocian 150 , P. Kodys 140 , T. Koffas 33 , E. Koffeman 118 , N.M. Köhler 113 , T. Koi 150 , M. Kolb 59b , I. Koletsou 5 , T. Kondo 79 , N. Kondrashova 58c , K. Köneke 50 , A.C. König 117 , T. Kono 79 , R. Konoplich 122,al , V. Konstantinides 92 , N. Konstantinidis 92 , B. Konya 94 , R. Kopeliansky 63 , S. Koperny 81a , K. Korcyl 82 , K. Kordas 159 , A. Korn 92 , I. Korolkov 14 , E.V. Korolkova 146 , O. Kortner 113 , S. Kortner 113 , T. Kosek 140 , V.V. Kostyukhin 24 , A. Kotwal 47 , A. Koulouris 10 , A. Kourkoumeli-Charalampidi 68a,68b , C. Kourkoumelis 9 , E. Kourlitis 146 , V. Kouskoura 29 , A.B. Kowalewska 82 , R. Kowalewski 173 , T.Z. Kowalski 81a , C. Kozakai 160 , W. Kozanecki 142 , A.S. Kozhin 121 , V.A. Kramarenko 111 , G. Kramberger 89 , D. Krasnopevtsev 110 , M.W. Krasny 133 , A. Krasznahorkay 35 , D. Krauss 113 , J.A. Kremer 81a , J. Kretzschmar 88 , P. Krieger 164 , K. Krizka 18 , K. Kroeninger 45 , H. Kroha 113 , J. Kroll 138 , J. Kroll 134 , J. Krstic 16 , U. Kruchonak 77 , H. Krüger 24 , N. Krumnack 76 , M.C. Kruse 47 , T. Kubota 102 , S. Kuday 4b , J.T. Kuechler 179 , S. Kuehn 35 , A. Kugel 59a , F. Kuger 174 , T. Kuhl 44 , V. Kukhtin 77 , R. Kukla 99 , Y. Kulchitsky 105 , S. Kuleshov 144b , Y.P. Kulinich 170 , M. Kuna 56 , T. Kunigo 83 , A. Kupco 138 , T. Kupfer 45 , O. Kuprash 158 , H. Kurashige 80 , L.L. Kurchaninov 165a , Y.A. Kurochkin 105 , M.G. Kurth 15d , E.S. Kuwertz 173 , M. Kuze 162 , J. Kvita 127 , T. Kwan 101 , A. La Rosa 113 , J.L. La Rosa Navarro 78d , L. La Rotonda 40b,40a , F. La Ruffa 40b,40a , C. Lacasta 171 , F. Lacava 70a,70b , J. Lacey 44 , D.P.J. Lack 98 , H. Lacker 19 , D. Lacour 133 , E. Ladygin 77 , R. Lafaye 5 , B. Laforge 133 , T. Lagouri 32c , S. Lai 51 , S. Lammers 63 , W. Lampl 7 , E. Lançon 29 , U. Landgraf 50 , M.P.J. Landon 90 , M.C. Lanfermann 52 , V.S. Lang 44 , J.C. Lange 14 , R.J. Langenberg 35 , A.J. Lankford 168 , F. Lanni 29 , K. Lantzsch 24 , A. Lanza 68a , A. Lapertosa 53b,53a , S. Laplace 133 , J.F. Laporte 142 , T. Lari 66a , F. Lasagni Manghi 23b,23a , M. Lassnig 35 , T.S. Lau 61a , A. Laudrain 129 , M. Lavorgna 67a,67b , A.T. Law 143 , P. Laycock 88 , M. Lazzaroni 66a,66b , B. Le 102 , O. Le Dortz 133 , E. Le Guirriec 99 , E.P. Le Quilleuc 142 , M. LeBlanc 7 , T. LeCompte 6 , F. Ledroit-Guillon 56 , C.A. Lee 29 , G.R. Lee 144a , L. Lee 57 , S.C. Lee 155 , B. Lefebvre 101 , M. Lefebvre 173 , F. Legger 112 , C. Leggett 18 , N. Lehmann 179 , G. Lehmann Miotto 35 , W.A. Leight 44 , A. Leisos 159,w , M.A.L. Leite 78d , R. Leitner 140 , D. Lellouch 177 , B. Lemmer 51 , K.J.C. Leney 92 , T. Lenz 24 , B. Lenzi 35 , R. Leone 7 , S. Leone 69a , C. Leonidopoulos 48 , G. Lerner 153 , C. Leroy 107 , R. Les 164 , A.A.J. Lesage 142 , C.G. Lester 31 , M. Levchenko 135 , J. Levêque 5 , D. Levin 103 , L.J. Levinson 177 , D. Lewis 90 , B. Li 103 , C-Q. Li 58a,ak , H. Li 58b , L. Li 58c , Q. Li 15d , Q.Y. Li 58a , S. Li 58d,58c , X. Li 58c , Y. Li 148 , Z. Liang 15a , B. Liberti 71a , A. Liblong 164 , K. Lie 61c , S. Liem 118 , A. Limosani 154 , C.Y. Lin 31 , K. Lin 104 , T.H. Lin 97 , R.A. Linck 63 , B.E. Lindquist 152 , A.L. Lionti 52 , E. Lipeles 134 , A. Lipniacka 17 , M. Lisovyi 59b , T.M. Liss 170,ar , A. Lister 172 , A.M. Litke 143 , J.D. Little 8 , B. Liu 76 , B.L Liu 6 , H.B. Liu 29 , H. Liu 103 , J.B. Liu 58a , J.K.K. Liu 132 , K. Liu 133 , M. Liu 58a , P. Liu 18 , Y. Liu 15a , Y.L. Liu 58a , Y.W. Liu 58a , M. Livan 68a,68b , A. Lleres 56 , J. Llorente Merino 15a , S.L. Lloyd 90 , C.Y. Lo 61b , F. Lo Sterzo 41 , E.M. Lobodzinska 44 , P. Loch 7 , K.M. Loew 26 , T. Lohse 19 , K. Lohwasser 146 , M. Lokajicek 138 , B.A. Long 25 , J.D. Long 170 , R.E. Long 87 , L. Longo 65a,65b , K.A. Looper 123 , J.A. Lopez 144b , I. Lopez Paz 14 , A. Lopez Solis 146 , J. Lorenz 112 , N. Lorenzo Martinez 5 , M. Losada 22 , P.J. Lösel 112 , A. Lösle 50 , X. Lou 44 , X. Lou 15a , A. Lounis 129 , J. Love 6 , P.A. Love 87 , J.J. Lozano Bahilo 171 , H. Lu 61a , M. Lu 58a , N. Lu 103 , Y.J. Lu 62 , H.J. Lubatti 145 , C. Luci 70a,70b , A. Lucotte 56 , C. Luedtke 50 , F. Luehring 63 , I. Luise 133 , W. Lukas 74 , L. Luminari 70a , B. Lund-Jensen 151 , M.S. Lutz 100 , P.M. Luzi 133 , D. Lynn 29 , R. Lysak 138 , E. Lytken 94 , F. Lyu 15a , V. Lyubushkin 77 , H. Ma 29 , L.L. Ma 58b , Y. Ma 58b , G. Maccarrone 49 , A. Macchiolo 113 , C.M. Macdonald 146 , J. Machado Miguens 134,137b , D. Madaffari 171 , R. Madar 37 , W.F. Mader 46 , A. Madsen 44 , N. Madysa 46 , J. Maeda 80 , K. Maekawa 160 , S. Maeland 17 , T. Maeno 29 , A.S. Maevskiy 111 , V. Magerl 50 , C. Maidantchik 78b , T. Maier 112 , A. Maio 137a,137b,137d , O. Majersky 28a , S. Majewski 128 , Y. Makida 79 , N. Makovec 129 , B. Malaescu 133 , Pa. Malecki 82 , V.P. Maleev 135 , F. Malek 56 , U. Mallik 75 , D. Malon 6 , C. Malone 31 , S. Maltezos 10 , S. Malyukov 35 , J. Mamuzic 171 , G. Mancini 49 , I. Mandić 89 , J. Maneira 137a , L. Manhaes de Andrade Filho 78a , J. Manjarres Ramos 46 , K.H. Mankinen 94 , A. Mann 112 , A. Manousos 74 , B. Mansoulie 142 , J.D. Mansour 15a , M. Mantoani 51 , S. Manzoni 66a,66b , G. Marceca 30 , L. March 52 , L. Marchese 132 , G. Marchiori 133 , M. Marcisovsky 138 , C.A. Marin Tobon 35 , M. Marjanovic 37 , D.E. Marley 103 , F. Marroquim 78b , Z. Marshall 18 , M.U.F Martensson 169 , S. Marti-Garcia 171 , C.B. Martin 123 , T.A. Martin 175 , V.J. Martin 48 , B. Martin dit Latour 17 , M. Martinez 14,z , V.I. Martinez Outschoorn 100 , S. Martin-Haugh 141 , V.S. Martoiu 27b , A.C. Martyniuk 92 , A. Marzin 35 , L. Masetti 97 , T. Mashimo 160 , R. Mashinistov 108 , J. Masik 98 , A.L. Maslennikov 120b,120a , L.H. Mason 102 , L. Massa 71a,71b , P. Mastrandrea 5 , A. Mastroberardino 40b,40a , T. Masubuchi 160 , P. Mättig 179 , J. Maurer 27b , The ATLAS Collaboration / Physics Letters B 793 (2019) 499–519 513 B. Maček 89 , S.J. Maxfield 88 , D.A. Maximov 120b,120a , R. Mazini 155 , I. Maznas 159 , S.M. Mazza 143 , N.C. Mc Fadden 116 , G. Mc Goldrick 164 , S.P. Mc Kee 103 , A. McCarn 103 , T.G. McCarthy 113 , L.I. McClymont 92 , E.F. McDonald 102 , J.A. Mcfayden 35 , G. Mchedlidze 51 , M.A. McKay 41 , K.D. McLean 173 , S.J. McMahon 141 , P.C. McNamara 102 , C.J. McNicol 175 , R.A. McPherson 173,ad , J.E. Mdhluli 32c , Z.A. Meadows 100 , S. Meehan 145 , T.M. Megy 50 , S. Mehlhase 112 , A. Mehta 88 , T. Meideck 56 , B. Meirose 42 , D. Melini 171,h , B.R. Mellado Garcia 32c , J.D. Mellenthin 51 , M. Melo 28a , F. Meloni 44 , A. Melzer 24 , S.B. Menary 98 , E.D. Mendes Gouveia 137a , L. Meng 88 , X.T. Meng 103 , A. Mengarelli 23b,23a , S. Menke 113 , E. Meoni 40b,40a , S. Mergelmeyer 19 , C. Merlassino 20 , P. Mermod 52 , L. Merola 67a,67b , C. Meroni 66a , F.S. Merritt 36 , A. Messina 70a,70b , J. Metcalfe 6 , A.S. Mete 168 , C. Meyer 134 , J. Meyer 157 , J-P. Meyer 142 , H. Meyer Zu Theenhausen 59a , F. Miano 153 , R.P. Middleton 141 , L. Mijović 48 , G. Mikenberg 177 , M. Mikestikova 138 , M. Mikuž 89 , M. Milesi 102 , A. Milic 164 , D.A. Millar 90 , D.W. Miller 36 , A. Milov 177 , D.A. Milstead 43a,43b , A.A. Minaenko 121 , M. Miñano Moya 171 , I.A. Minashvili 156b , A.I. Mincer 122 , B. Mindur 81a , M. Mineev 77 , Y. Minegishi 160 , Y. Ming 178 , L.M. Mir 14 , A. Mirto 65a,65b , K.P. Mistry 134 , T. Mitani 176 , J. Mitrevski 112 , V.A. Mitsou 171 , A. Miucci 20 , P.S. Miyagawa 146 , A. Mizukami 79 , J.U. Mjörnmark 94 , T. Mkrtchyan 181 , M. Mlynarikova 140 , T. Moa 43a,43b , K. Mochizuki 107 , P. Mogg 50 , S. Mohapatra 38 , S. Molander 43a,43b , R. Moles-Valls 24 , M.C. Mondragon 104 , K. Mönig 44 , J. Monk 39 , E. Monnier 99 , A. Montalbano 149 , J. Montejo Berlingen 35 , F. Monticelli 86 , S. Monzani 66a , R.W. Moore 3 , N. Morange 129 , D. Moreno 22 , M. Moreno Llácer 35 , P. Morettini 53b , M. Morgenstern 118 , S. Morgenstern 46 , D. Mori 149 , T. Mori 160 , M. Morii 57 , M. Morinaga 176 , V. Morisbak 131 , A.K. Morley 35 , G. Mornacchi 35 , A.P. Morris 92 , J.D. Morris 90 , L. Morvaj 152 , P. Moschovakos 10 , M. Mosidze 156b , H.J. Moss 146 , J. Moss 150,n , K. Motohashi 162 , R. Mount 150 , E. Mountricha 35 , E.J.W. Moyse 100 , S. Muanza 99 , F. Mueller 113 , J. Mueller 136 , R.S.P. Mueller 112 , D. Muenstermann 87 , P. Mullen 55 , G.A. Mullier 20 , F.J. Munoz Sanchez 98 , P. Murin 28b , W.J. Murray 175,141 , A. Murrone 66a,66b , M. Muškinja 89 , C. Mwewa 32a , A.G. Myagkov 121,am , J. Myers 128 , M. Myska 139 , B.P. Nachman 18 , O. Nackenhorst 45 , K. Nagai 132 , K. Nagano 79 , Y. Nagasaka 60 , K. Nagata 166 , M. Nagel 50 , E. Nagy 99 , A.M. Nairz 35 , Y. Nakahama 115 , K. Nakamura 79 , T. Nakamura 160 , I. Nakano 124 , H. Nanjo 130 , F. Napolitano 59a , R.F. Naranjo Garcia 44 , R. Narayan 11 , D.I. Narrias Villar 59a , I. Naryshkin 135 , T. Naumann 44 , G. Navarro 22 , R. Nayyar 7 , H.A. Neal 103,∗ , P.Y. Nechaeva 108 , T.J. Neep 142 , A. Negri 68a,68b , M. Negrini 23b , S. Nektarijevic 117 , C. Nellist 51 , M.E. Nelson 132 , S. Nemecek 138 , P. Nemethy 122 , M. Nessi 35,f , M.S. Neubauer 170 , M. Neumann 179 , P.R. Newman 21 , T.Y. Ng 61c , Y.S. Ng 19 , H.D.N. Nguyen 99 , T. Nguyen Manh 107 , E. Nibigira 37 , R.B. Nickerson 132 , R. Nicolaidou 142 , J. Nielsen 143 , N. Nikiforou 11 , V. Nikolaenko 121,am , I. Nikolic-Audit 133 , K. Nikolopoulos 21 , P. Nilsson 29 , Y. Ninomiya 79 , A. Nisati 70a , N. Nishu 58c , R. Nisius 113 , I. Nitsche 45 , T. Nitta 176 , T. Nobe 160 , Y. Noguchi 83 , M. Nomachi 130 , I. Nomidis 133 , M.A. Nomura 29 , T. Nooney 90 , M. Nordberg 35 , N. Norjoharuddeen 132 , T. Novak 89 , O. Novgorodova 46 , R. Novotny 139 , L. Nozka 127 , K. Ntekas 168 , E. Nurse 92 , F. Nuti 102 , F.G. Oakham 33,au , H. Oberlack 113 , T. Obermann 24 , J. Ocariz 133 , A. Ochi 80 , I. Ochoa 38 , J.P. Ochoa-Ricoux 144a , K. O’Connor 26 , S. Oda 85 , S. Odaka 79 , S. Oerdek 51 , A. Oh 98 , S.H. Oh 47 , C.C. Ohm 151 , H. Oide 53b,53a , H. Okawa 166 , Y. Okazaki 83 , Y. Okumura 160 , T. Okuyama 79 , A. Olariu 27b , L.F. Oleiro Seabra 137a , S.A. Olivares Pino 144a , D. Oliveira Damazio 29 , J.L. Oliver 1 , M.J.R. Olsson 36 , A. Olszewski 82 , J. Olszowska 82 , D.C. O’Neil 149 , A. Onofre 137a,137e , K. Onogi 115 , P.U.E. Onyisi 11 , H. Oppen 131 , M.J. Oreglia 36 , Y. Oren 158 , D. Orestano 72a,72b , E.C. Orgill 98 , N. Orlando 61b , A.A. O’Rourke 44 , R.S. Orr 164 , B. Osculati 53b,53a,∗ , V. O’Shea 55 , R. Ospanov 58a , G. Otero y Garzon 30 , H. Otono 85 , M. Ouchrif 34d , F. Ould-Saada 131 , A. Ouraou 142 , Q. Ouyang 15a , M. Owen 55 , R.E. Owen 21 , V.E. Ozcan 12c , N. Ozturk 8 , J. Pacalt 127 , H.A. Pacey 31 , K. Pachal 149 , A. Pacheco Pages 14 , L. Pacheco Rodriguez 142 , C. Padilla Aranda 14 , S. Pagan Griso 18 , M. Paganini 180 , G. Palacino 63 , S. Palazzo 40b,40a , S. Palestini 35 , M. Palka 81b , D. Pallin 37 , I. Panagoulias 10 , C.E. Pandini 35 , J.G. Panduro Vazquez 91 , P. Pani 35 , G. Panizzo 64a,64c , L. Paolozzi 52 , T.D. Papadopoulou 10 , K. Papageorgiou 9,j , A. Paramonov 6 , D. Paredes Hernandez 61b , S.R. Paredes Saenz 132 , B. Parida 58c , A.J. Parker 87 , K.A. Parker 44 , M.A. Parker 31 , F. Parodi 53b,53a , J.A. Parsons 38 , U. Parzefall 50 , V.R. Pascuzzi 164 , J.M.P. Pasner 143 , E. Pasqualucci 70a , S. Passaggio 53b , F. Pastore 91 , P. Pasuwan 43a,43b , S. Pataraia 97 , J.R. Pater 98 , A. Pathak 178,k , T. Pauly 35 , B. Pearson 113 , M. Pedersen 131 , L. Pedraza Diaz 117 , R. Pedro 137a,137b , S.V. Peleganchuk 120b,120a , O. Penc 138 , C. Peng 15d , H. Peng 58a , B.S. Peralva 78a , M.M. Perego 142 , A.P. Pereira Peixoto 137a , D.V. Perepelitsa 29 , F. Peri 19 , L. Perini 66a,66b , H. Pernegger 35 , S. Perrella 67a,67b , V.D. Peshekhonov 77,∗ , K. Peters 44 , R.F.Y. Peters 98 , 514 The ATLAS Collaboration / Physics Letters B 793 (2019) 499–519 B.A. Petersen 35 , T.C. Petersen 39 , E. Petit 56 , A. Petridis 1 , C. Petridou 159 , P. Petroff 129 , E. Petrolo 70a , M. Petrov 132 , F. Petrucci 72a,72b , M. Pettee 180 , N.E. Pettersson 100 , A. Peyaud 142 , R. Pezoa 144b , T. Pham 102 , F.H. Phillips 104 , P.W. Phillips 141 , G. Piacquadio 152 , E. Pianori 18 , A. Picazio 100 , M.A. Pickering 132 , R. Piegaia 30 , J.E. Pilcher 36 , A.D. Pilkington 98 , M. Pinamonti 71a,71b , J.L. Pinfold 3 , M. Pitt 177 , M.-A. Pleier 29 , V. Pleskot 140 , E. Plotnikova 77 , D. Pluth 76 , P. Podberezko 120b,120a , R. Poettgen 94 , R. Poggi 52 , L. Poggioli 129 , I. Pogrebnyak 104 , D. Pohl 24 , I. Pokharel 51 , G. Polesello 68a , A. Poley 44 , A. Policicchio 40b,40a , R. Polifka 35 , A. Polini 23b , C.S. Pollard 44 , V. Polychronakos 29 , D. Ponomarenko 110 , L. Pontecorvo 35 , G.A. Popeneciu 27d , D.M. Portillo Quintero 133 , S. Pospisil 139 , K. Potamianos 44 , I.N. Potrap 77 , C.J. Potter 31 , H. Potti 11 , T. Poulsen 94 , J. Poveda 35 , T.D. Powell 146 , M.E. Pozo Astigarraga 35 , P. Pralavorio 99 , S. Prell 76 , D. Price 98 , M. Primavera 65a , S. Prince 101 , N. Proklova 110 , K. Prokofiev 61c , F. Prokoshin 144b , S. Protopopescu 29 , J. Proudfoot 6 , M. Przybycien 81a , A. Puri 170 , P. Puzo 129 , J. Qian 103 , Y. Qin 98 , A. Quadt 51 , M. Queitsch-Maitland 44 , A. Qureshi 1 , P. Rados 102 , F. Ragusa 66a,66b , G. Rahal 95 , J.A. Raine 98 , S. Rajagopalan 29 , A. Ramirez Morales 90 , T. Rashid 129 , S. Raspopov 5 , M.G. Ratti 66a,66b , D.M. Rauch 44 , F. Rauscher 112 , S. Rave 97 , B. Ravina 146 , I. Ravinovich 177 , J.H. Rawling 98 , M. Raymond 35 , A.L. Read 131 , N.P. Readioff 56 , M. Reale 65a,65b , D.M. Rebuzzi 68a,68b , A. Redelbach 174 , G. Redlinger 29 , R. Reece 143 , R.G. Reed 32c , K. Reeves 42 , L. Rehnisch 19 , J. Reichert 134 , A. Reiss 97 , C. Rembser 35 , H. Ren 15d , M. Rescigno 70a , S. Resconi 66a , E.D. Resseguie 134 , S. Rettie 172 , E. Reynolds 21 , O.L. Rezanova 120b,120a , P. Reznicek 140 , R. Richter 113 , S. Richter 92 , E. Richter-Was 81b , O. Ricken 24 , M. Ridel 133 , P. Rieck 113 , C.J. Riegel 179 , O. Rifki 44 , M. Rijssenbeek 152 , A. Rimoldi 68a,68b , M. Rimoldi 20 , L. Rinaldi 23b , G. Ripellino 151 , B. Ristić 87 , E. Ritsch 35 , I. Riu 14 , J.C. Rivera Vergara 144a , F. Rizatdinova 126 , E. Rizvi 90 , C. Rizzi 14 , R.T. Roberts 98 , S.H. Robertson 101,ad , A. Robichaud-Veronneau 101 , D. Robinson 31 , J.E.M. Robinson 44 , A. Robson 55 , E. Rocco 97 , C. Roda 69a,69b , Y. Rodina 99 , S. Rodriguez Bosca 171 , A. Rodriguez Perez 14 , D. Rodriguez Rodriguez 171 , A.M. Rodríguez Vera 165b , S. Roe 35 , C.S. Rogan 57 , O. Røhne 131 , R. Röhrig 113 , C.P.A. Roland 63 , J. Roloff 57 , A. Romaniouk 110 , M. Romano 23b,23a , N. Rompotis 88 , M. Ronzani 122 , L. Roos 133 , S. Rosati 70a , K. Rosbach 50 , P. Rose 143 , N-A. Rosien 51 , E. Rossi 67a,67b , L.P. Rossi 53b , L. Rossini 66a,66b , J.H.N. Rosten 31 , R. Rosten 14 , M. Rotaru 27b , J. Rothberg 145 , D. Rousseau 129 , D. Roy 32c , A. Rozanov 99 , Y. Rozen 157 , X. Ruan 32c , F. Rubbo 150 , F. Rühr 50 , A. Ruiz-Martinez 171 , Z. Rurikova 50 , N.A. Rusakovich 77 , H.L. Russell 101 , J.P. Rutherfoord 7 , E.M. Rüttinger 44,l , Y.F. Ryabov 135 , M. Rybar 170 , G. Rybkin 129 , S. Ryu 6 , A. Ryzhov 121 , G.F. Rzehorz 51 , P. Sabatini 51 , G. Sabato 118 , S. Sacerdoti 129 , H.F-W. Sadrozinski 143 , R. Sadykov 77 , F. Safai Tehrani 70a , P. Saha 119 , M. Sahinsoy 59a , A. Sahu 179 , M. Saimpert 44 , M. Saito 160 , T. Saito 160 , H. Sakamoto 160 , A. Sakharov 122,al , D. Salamani 52 , G. Salamanna 72a,72b , J.E. Salazar Loyola 144b , D. Salek 118 , P.H. Sales De Bruin 169 , D. Salihagic 113 , A. Salnikov 150 , J. Salt 171 , D. Salvatore 40b,40a , F. Salvatore 153 , A. Salvucci 61a,61b,61c , A. Salzburger 35 , J. Samarati 35 , D. Sammel 50 , D. Sampsonidis 159 , D. Sampsonidou 159 , J. Sánchez 171 , A. Sanchez Pineda 64a,64c , H. Sandaker 131 , C.O. Sander 44 , M. Sandhoff 179 , C. Sandoval 22 , D.P.C. Sankey 141 , M. Sannino 53b,53a , Y. Sano 115 , A. Sansoni 49 , C. Santoni 37 , H. Santos 137a , I. Santoyo Castillo 153 , A. Sapronov 77 , J.G. Saraiva 137a,137d , O. Sasaki 79 , K. Sato 166 , E. Sauvan 5 , P. Savard 164,au , N. Savic 113 , R. Sawada 160 , C. Sawyer 141 , L. Sawyer 93,aj , C. Sbarra 23b , A. Sbrizzi 23b,23a , T. Scanlon 92 , J. Schaarschmidt 145 , P. Schacht 113 , B.M. Schachtner 112 , D. Schaefer 36 , L. Schaefer 134 , J. Schaeffer 97 , S. Schaepe 35 , U. Schäfer 97 , A.C. Schaffer 129 , D. Schaile 112 , R.D. Schamberger 152 , N. Scharmberg 98 , V.A. Schegelsky 135 , D. Scheirich 140 , F. Schenck 19 , M. Schernau 168 , C. Schiavi 53b,53a , S. Schier 143 , L.K. Schildgen 24 , Z.M. Schillaci 26 , E.J. Schioppa 35 , M. Schioppa 40b,40a , K.E. Schleicher 50 , S. Schlenker 35 , K.R. Schmidt-Sommerfeld 113 , K. Schmieden 35 , C. Schmitt 97 , S. Schmitt 44 , S. Schmitz 97 , U. Schnoor 50 , L. Schoeffel 142 , A. Schoening 59b , E. Schopf 24 , M. Schott 97 , J.F.P. Schouwenberg 117 , J. Schovancova 35 , S. Schramm 52 , A. Schulte 97 , H-C. Schultz-Coulon 59a , M. Schumacher 50 , B.A. Schumm 143 , Ph. Schune 142 , A. Schwartzman 150 , T.A. Schwarz 103 , H. Schweiger 98 , Ph. Schwemling 142 , R. Schwienhorst 104 , A. Sciandra 24 , G. Sciolla 26 , M. Scornajenghi 40b,40a , F. Scuri 69a , F. Scutti 102 , L.M. Scyboz 113 , J. Searcy 103 , C.D. Sebastiani 70a,70b , P. Seema 24 , S.C. Seidel 116 , A. Seiden 143 , T. Seiss 36 , J.M. Seixas 78b , G. Sekhniaidze 67a , K. Sekhon 103 , S.J. Sekula 41 , N. Semprini-Cesari 23b,23a , S. Sen 47 , S. Senkin 37 , C. Serfon 131 , L. Serin 129 , L. Serkin 64a,64b , M. Sessa 72a,72b , H. Severini 125 , F. Sforza 167 , A. Sfyrla 52 , E. Shabalina 51 , J.D. Shahinian 143 , N.W. Shaikh 43a,43b , L.Y. Shan 15a , R. Shang 170 , J.T. Shank 25 , M. Shapiro 18 , A.S. Sharma 1 , A. Sharma 132 , P.B. Shatalov 109 , K. Shaw 153 , S.M. Shaw 98 , A. Shcherbakova 135 , Y. Shen 125 , N. Sherafati 33 , The ATLAS Collaboration / Physics Letters B 793 (2019) 499–519 515 A.D. Sherman 25 , P. Sherwood 92 , L. Shi 155,aq , S. Shimizu 80 , C.O. Shimmin 180 , M. Shimojima 114 , I.P.J. Shipsey 132 , S. Shirabe 85 , M. Shiyakova 77 , J. Shlomi 177 , A. Shmeleva 108 , D. Shoaleh Saadi 107 , M.J. Shochet 36 , S. Shojaii 102 , D.R. Shope 125 , S. Shrestha 123 , E. Shulga 110 , P. Sicho 138 , A.M. Sickles 170 , P.E. Sidebo 151 , E. Sideras Haddad 32c , O. Sidiropoulou 174 , A. Sidoti 23b,23a , F. Siegert 46 , Dj. Sijacki 16 , J. Silva 137a , M. Silva Jr. 178 , M.V. Silva Oliveira 78a , S.B. Silverstein 43a , L. Simic 77 , S. Simion 129 , E. Simioni 97 , M. Simon 97 , R. Simoniello 97 , P. Sinervo 164 , N.B. Sinev 128 , M. Sioli 23b,23a , G. Siragusa 174 , I. Siral 103 , S.Yu. Sivoklokov 111 , J. Sjölin 43a,43b , M.B. Skinner 87 , P. Skubic 125 , M. Slater 21 , T. Slavicek 139 , M. Slawinska 82 , K. Sliwa 167 , R. Slovak 140 , V. Smakhtin 177 , B.H. Smart 5 , J. Smiesko 28a , N. Smirnov 110 , S.Yu. Smirnov 110 , Y. Smirnov 110 , L.N. Smirnova 111 , O. Smirnova 94 , J.W. Smith 51 , M.N.K. Smith 38 , R.W. Smith 38 , M. Smizanska 87 , K. Smolek 139 , A.A. Snesarev 108 , I.M. Snyder 128 , S. Snyder 29 , R. Sobie 173,ad , A.M. Soffa 168 , A. Soffer 158 , A. Søgaard 48 , D.A. Soh 155 , G. Sokhrannyi 89 , C.A. Solans Sanchez 35 , M. Solar 139 , E.Yu. Soldatov 110 , U. Soldevila 171 , A.A. Solodkov 121 , A. Soloshenko 77 , O.V. Solovyanov 121 , V. Solovyev 135 , P. Sommer 146 , H. Son 167 , W. Song 141 , A. Sopczak 139 , F. Sopkova 28b , D. Sosa 59b , C.L. Sotiropoulou 69a,69b , S. Sottocornola 68a,68b , R. Soualah 64a,64c,i , A.M. Soukharev 120b,120a , D. South 44 , B.C. Sowden 91 , S. Spagnolo 65a,65b , M. Spalla 113 , M. Spangenberg 175 , F. Spanò 91 , D. Sperlich 19 , F. Spettel 113 , T.M. Spieker 59a , R. Spighi 23b , G. Spigo 35 , L.A. Spiller 102 , D.P. Spiteri 55 , M. Spousta 140 , A. Stabile 66a,66b , R. Stamen 59a , S. Stamm 19 , E. Stanecka 82 , R.W. Stanek 6 , C. Stanescu 72a , B. Stanislaus 132 , M.M. Stanitzki 44 , B. Stapf 118 , S. Stapnes 131 , E.A. Starchenko 121 , G.H. Stark 36 , J. Stark 56 , S.H Stark 39 , P. Staroba 138 , P. Starovoitov 59a , S. Stärz 35 , R. Staszewski 82 , M. Stegler 44 , P. Steinberg 29 , B. Stelzer 149 , H.J. Stelzer 35 , O. Stelzer-Chilton 165a , H. Stenzel 54 , T.J. Stevenson 90 , G.A. Stewart 55 , M.C. Stockton 128 , G. Stoicea 27b , P. Stolte 51 , S. Stonjek 113 , A. Straessner 46 , J. Strandberg 151 , S. Strandberg 43a,43b , M. Strauss 125 , P. Strizenec 28b , R. Ströhmer 174 , D.M. Strom 128 , R. Stroynowski 41 , A. Strubig 48 , S.A. Stucci 29 , B. Stugu 17 , J. Stupak 125 , N.A. Styles 44 , D. Su 150 , J. Su 136 , S. Suchek 59a , Y. Sugaya 130 , M. Suk 139 , V.V. Sulin 108 , D.M.S. Sultan 52 , S. Sultansoy 4c , T. Sumida 83 , S. Sun 103 , X. Sun 3 , K. Suruliz 153 , C.J.E. Suster 154 , M.R. Sutton 153 , S. Suzuki 79 , M. Svatos 138 , M. Swiatlowski 36 , S.P. Swift 2 , A. Sydorenko 97 , I. Sykora 28a , T. Sykora 140 , D. Ta 97 , K. Tackmann 44,aa , J. Taenzer 158 , A. Taffard 168 , R. Tafirout 165a , E. Tahirovic 90 , N. Taiblum 158 , H. Takai 29 , R. Takashima 84 , E.H. Takasugi 113 , K. Takeda 80 , T. Takeshita 147 , Y. Takubo 79 , M. Talby 99 , A.A. Talyshev 120b,120a , J. Tanaka 160 , M. Tanaka 162 , R. Tanaka 129 , R. Tanioka 80 , B.B. Tannenwald 123 , S. Tapia Araya 144b , S. Tapprogge 97 , A. Tarek Abouelfadl Mohamed 133 , S. Tarem 157 , G. Tarna 27b,e , G.F. Tartarelli 66a , P. Tas 140 , M. Tasevsky 138 , T. Tashiro 83 , E. Tassi 40b,40a , A. Tavares Delgado 137a,137b , Y. Tayalati 34e , A.C. Taylor 116 , A.J. Taylor 48 , G.N. Taylor 102 , P.T.E. Taylor 102 , W. Taylor 165b , A.S. Tee 87 , P. Teixeira-Dias 91 , H. Ten Kate 35 , P.K. Teng 155 , J.J. Teoh 118 , F. Tepel 179 , S. Terada 79 , K. Terashi 160 , J. Terron 96 , S. Terzo 14 , M. Testa 49 , R.J. Teuscher 164,ad , S.J. Thais 180 , T. Theveneaux-Pelzer 44 , F. Thiele 39 , J.P. Thomas 21 , A.S. Thompson 55 , P.D. Thompson 21 , L.A. Thomsen 180 , E. Thomson 134 , Y. Tian 38 , R.E. Ticse Torres 51 , V.O. Tikhomirov 108,an , Yu.A. Tikhonov 120b,120a , S. Timoshenko 110 , P. Tipton 180 , S. Tisserant 99 , K. Todome 162 , S. Todorova-Nova 5 , S. Todt 46 , J. Tojo 85 , S. Tokár 28a , K. Tokushuku 79 , E. Tolley 123 , K.G. Tomiwa 32c , M. Tomoto 115 , L. Tompkins 150,q , K. Toms 116 , B. Tong 57 , P. Tornambe 50 , E. Torrence 128 , H. Torres 46 , E. Torró Pastor 145 , C. Tosciri 132 , J. Toth 99,ac , F. Touchard 99 , D.R. Tovey 146 , C.J. Treado 122 , T. Trefzger 174 , F. Tresoldi 153 , A. Tricoli 29 , I.M. Trigger 165a , S. Trincaz-Duvoid 133 , M.F. Tripiana 14 , W. Trischuk 164 , B. Trocmé 56 , A. Trofymov 129 , C. Troncon 66a , M. Trovatelli 173 , F. Trovato 153 , L. Truong 32b , M. Trzebinski 82 , A. Trzupek 82 , F. Tsai 44 , J.C-L. Tseng 132 , P.V. Tsiareshka 105 , N. Tsirintanis 9 , V. Tsiskaridze 152 , E.G. Tskhadadze 156a , I.I. Tsukerman 109 , V. Tsulaia 18 , S. Tsuno 79 , D. Tsybychev 152 , Y. Tu 61b , A. Tudorache 27b , V. Tudorache 27b , T.T. Tulbure 27a , A.N. Tuna 57 , S. Turchikhin 77 , D. Turgeman 177 , I. Turk Cakir 4b,u , R. Turra 66a , P.M. Tuts 38 , E. Tzovara 97 , G. Ucchielli 23b,23a , I. Ueda 79 , M. Ughetto 43a,43b , F. Ukegawa 166 , G. Unal 35 , A. Undrus 29 , G. Unel 168 , F.C. Ungaro 102 , Y. Unno 79 , K. Uno 160 , J. Urban 28b , P. Urquijo 102 , P. Urrejola 97 , G. Usai 8 , J. Usui 79 , L. Vacavant 99 , V. Vacek 139 , B. Vachon 101 , K.O.H. Vadla 131 , A. Vaidya 92 , C. Valderanis 112 , E. Valdes Santurio 43a,43b , M. Valente 52 , S. Valentinetti 23b,23a , A. Valero 171 , L. Valéry 44 , R.A. Vallance 21 , A. Vallier 5 , J.A. Valls Ferrer 171 , T.R. Van Daalen 14 , W. Van Den Wollenberg 118 , H. Van der Graaf 118 , P. Van Gemmeren 6 , J. Van Nieuwkoop 149 , I. Van Vulpen 118 , M. Vanadia 71a,71b , W. Vandelli 35 , A. Vaniachine 163 , P. Vankov 118 , R. Vari 70a , E.W. Varnes 7 , C. Varni 53b,53a , T. Varol 41 , D. Varouchas 129 , K.E. Varvell 154 , G.A. Vasquez 144b , J.G. Vasquez 180 , F. Vazeille 37 , D. Vazquez Furelos 14 , 516 The ATLAS Collaboration / Physics Letters B 793 (2019) 499–519 T. Vazquez Schroeder 101 , J. Veatch 51 , V. Vecchio 72a,72b , L.M. Veloce 164 , F. Veloso 137a,137c , S. Veneziano 70a , A. Ventura 65a,65b , M. Venturi 173 , N. Venturi 35 , V. Vercesi 68a , M. Verducci 72a,72b , C.M. Vergel Infante 76 , W. Verkerke 118 , A.T. Vermeulen 118 , J.C. Vermeulen 118 , M.C. Vetterli 149,au , N. Viaux Maira 144b , M. Vicente Barreto Pinto 52 , I. Vichou 170,∗ , T. Vickey 146 , O.E. Vickey Boeriu 146 , G.H.A. Viehhauser 132 , S. Viel 18 , L. Vigani 132 , M. Villa 23b,23a , M. Villaplana Perez 66a,66b , E. Vilucchi 49 , M.G. Vincter 33 , V.B. Vinogradov 77 , A. Vishwakarma 44 , C. Vittori 23b,23a , I. Vivarelli 153 , S. Vlachos 10 , M. Vogel 179 , P. Vokac 139 , G. Volpi 14 , S.E. von Buddenbrock 32c , E. Von Toerne 24 , V. Vorobel 140 , K. Vorobev 110 , M. Vos 171 , J.H. Vossebeld 88 , N. Vranjes 16 , M. Vranjes Milosavljevic 16 , V. Vrba 139 , M. Vreeswijk 118 , T. Šfiligoj 89 , R. Vuillermet 35 , I. Vukotic 36 , T. Ženiš 28a , L. Živković 16 , P. Wagner 24 , W. Wagner 179 , J. Wagner-Kuhr 112 , H. Wahlberg 86 , S. Wahrmund 46 , K. Wakamiya 80 , V.M. Walbrecht 113 , J. Walder 87 , R. Walker 112 , S.D. Walker 91 , W. Walkowiak 148 , V. Wallangen 43a,43b , A.M. Wang 57 , C. Wang 58b,e , F. Wang 178 , H. Wang 18 , H. Wang 3 , J. Wang 154 , J. Wang 59b , P. Wang 41 , Q. Wang 125 , R.-J. Wang 133 , R. Wang 58a , R. Wang 6 , S.M. Wang 155 , W.T. Wang 58a , W. Wang 15c,ae , W.X. Wang 58a,ae , Y. Wang 58a,ak , Z. Wang 58c , C. Wanotayaroj 44 , A. Warburton 101 , C.P. Ward 31 , D.R. Wardrope 92 , A. Washbrook 48 , P.M. Watkins 21 , A.T. Watson 21 , M.F. Watson 21 , G. Watts 145 , S. Watts 98 , B.M. Waugh 92 , A.F. Webb 11 , S. Webb 97 , C. Weber 180 , M.S. Weber 20 , S.A. Weber 33 , S.M. Weber 59a , J.S. Webster 6 , A.R. Weidberg 132 , B. Weinert 63 , J. Weingarten 51 , M. Weirich 97 , C. Weiser 50 , P.S. Wells 35 , T. Wenaus 29 , T. Wengler 35 , S. Wenig 35 , N. Wermes 24 , M.D. Werner 76 , P. Werner 35 , M. Wessels 59a , T.D. Weston 20 , K. Whalen 128 , N.L. Whallon 145 , A.M. Wharton 87 , A.S. White 103 , A. White 8 , M.J. White 1 , R. White 144b , D. Whiteson 168 , B.W. Whitmore 87 , F.J. Wickens 141 , W. Wiedenmann 178 , M. Wielers 141 , C. Wiglesworth 39 , L.A.M. Wiik-Fuchs 50 , A. Wildauer 113 , F. Wilk 98 , H.G. Wilkens 35 , L.J. Wilkins 91 , H.H. Williams 134 , S. Williams 31 , C. Willis 104 , S. Willocq 100 , J.A. Wilson 21 , I. Wingerter-Seez 5 , E. Winkels 153 , F. Winklmeier 128 , O.J. Winston 153 , B.T. Winter 24 , M. Wittgen 150 , M. Wobisch 93 , A. Wolf 97 , T.M.H. Wolf 118 , R. Wolff 99 , M.W. Wolter 82 , H. Wolters 137a,137c , V.W.S. Wong 172 , N.L. Woods 143 , S.D. Worm 21 , B.K. Wosiek 82 , K.W. Woźniak 82 , K. Wraight 55 , M. Wu 36 , S.L. Wu 178 , X. Wu 52 , Y. Wu 58a , T.R. Wyatt 98 , B.M. Wynne 48 , S. Xella 39 , Z. Xi 103 , L. Xia 175 , D. Xu 15a , H. Xu 58a,e , L. Xu 29 , T. Xu 142 , W. Xu 103 , B. Yabsley 154 , S. Yacoob 32a , K. Yajima 130 , D.P. Yallup 92 , D. Yamaguchi 162 , Y. Yamaguchi 162 , A. Yamamoto 79 , T. Yamanaka 160 , F. Yamane 80 , M. Yamatani 160 , T. Yamazaki 160 , Y. Yamazaki 80 , Z. Yan 25 , H.J. Yang 58c,58d , H.T. Yang 18 , S. Yang 75 , Y. Yang 160 , Z. Yang 17 , W-M. Yao 18 , Y.C. Yap 44 , Y. Yasu 79 , E. Yatsenko 58c,58d , J. Ye 41 , S. Ye 29 , I. Yeletskikh 77 , E. Yigitbasi 25 , E. Yildirim 97 , K. Yorita 176 , K. Yoshihara 134 , C.J.S. Young 35 , C. Young 150 , J. Yu 8 , J. Yu 76 , X. Yue 59a , S.P.Y. Yuen 24 , B. Zabinski 82 , G. Zacharis 10 , E. Zaffaroni 52 , R. Zaidan 14 , A.M. Zaitsev 121,am , N. Zakharchuk 44 , J. Zalieckas 17 , S. Zambito 57 , D. Zanzi 35 , D.R. Zaripovas 55 , S.V. Zeißner 45 , C. Zeitnitz 179 , G. Zemaityte 132 , J.C. Zeng 170 , Q. Zeng 150 , O. Zenin 121 , D. Zerwas 129 , M. Zgubič 132 , D.F. Zhang 58b , D. Zhang 103 , F. Zhang 178 , G. Zhang 58a , H. Zhang 15c , J. Zhang 6 , L. Zhang 15c , L. Zhang 58a , M. Zhang 170 , P. Zhang 15c , R. Zhang 58a , R. Zhang 24 , X. Zhang 58b , Y. Zhang 15d , Z. Zhang 129 , P. Zhao 47 , X. Zhao 41 , Y. Zhao 58b,129,ai , Z. Zhao 58a , A. Zhemchugov 77 , B. Zhou 103 , C. Zhou 178 , L. Zhou 41 , M.S. Zhou 15d , M. Zhou 152 , N. Zhou 58c , Y. Zhou 7 , C.G. Zhu 58b , H.L. Zhu 58a , H. Zhu 15a , J. Zhu 103 , Y. Zhu 58a , X. Zhuang 15a , K. Zhukov 108 , V. Zhulanov 120b,120a , A. Zibell 174 , D. Zieminska 63 , N.I. Zimine 77 , S. Zimmermann 50 , Z. Zinonos 113 , M. Zinser 97 , M. Ziolkowski 148 , G. Zobernig 178 , A. Zoccoli 23b,23a , K. Zoch 51 , T.G. Zorbas 146 , R. Zou 36 , M. Zur Nedden 19 , L. Zwalinski 35 1 Department of Physics, University of Adelaide, Adelaide, Australia 2 Physics Department, SUNY Albany, Albany, NY, United States of America 3 Department of Physics, University of Alberta, Edmonton, AB, Canada 4 (a) Department of Physics, Ankara University, Ankara; (b) Istanbul Aydin University, Istanbul; (c) Division of Physics, TOBB University of Economics and Technology, Ankara, Turkey 5 LAPP, Université Grenoble Alpes, Université Savoie Mont Blanc, CNRS/IN2P3, Annecy, France 6 High Energy Physics Division, Argonne National Laboratory, Argonne, IL, United States of America 7 Department of Physics, University of Arizona, Tucson, AZ, United States of America 8 Department of Physics, University of Texas at Arlington, Arlington, TX, United States of America 9 Physics Department, National and Kapodistrian University of Athens, Athens, Greece 10 Physics Department, National Technical University of Athens, Zografou, Greece 11 Department of Physics, University of Texas at Austin, Austin, TX, United States of America 12 (a) Bahcesehir University, Faculty of Engineering and Natural Sciences, Istanbul; (b) Istanbul Bilgi University, Faculty of Engineering and Natural Sciences, Istanbul; (c) Department of Physics, Bogazici University, Istanbul; (d) Department of Physics Engineering, Gaziantep University, Gaziantep, Turkey 13 Institute of Physics, Azerbaijan Academy of Sciences, Baku, Azerbaijan 14 Institut de Física d’Altes Energies (IFAE), Barcelona Institute of Science and Technology, Barcelona, Spain 15 (a) Institute of High Energy Physics, Chinese Academy of Sciences, Beijing; (b) Physics Department, Tsinghua University, Beijing; (c) Department of Physics, Nanjing University, Nanjing; (d) University of Chinese Academy of Science (UCAS), Beijing, China The ATLAS Collaboration / Physics Letters B 793 (2019) 499–519 517 16 Institute of Physics, University of Belgrade, Belgrade, Serbia 17 Department for Physics and Technology, University of Bergen, Bergen, Norway 18 Physics Division, Lawrence Berkeley National Laboratory and University of California, Berkeley, CA, United States of America 19 Institut für Physik, Humboldt Universität zu Berlin, Berlin, Germany 20 Albert Einstein Center for Fundamental Physics and Laboratory for High Energy Physics, University of Bern, Bern, Switzerland 21 School of Physics and Astronomy, University of Birmingham, Birmingham, United Kingdom 22 Centro de Investigaciónes, Universidad Antonio Nariño, Bogota, Colombia 23 (a) Dipartimento di Fisica e Astronomia, Università di Bologna, Bologna; (b) INFN Sezione di Bologna, Italy 24 Physikalisches Institut, Universität Bonn, Bonn, Germany 25 Department of Physics, Boston University, Boston, MA, United States of America 26 Department of Physics, Brandeis University, Waltham, MA, United States of America 27 (a) Transilvania University of Brasov, Brasov; (b) Horia Hulubei National Institute of Physics and Nuclear Engineering, Bucharest; (c) Department of Physics, Alexandru Ioan Cuza University of Iasi, Iasi; (d) National Institute for Research and Development of Isotopic and Molecular Technologies, Physics Department, Cluj-Napoca; (e) University Politehnica Bucharest, Bucharest; (f ) West University in Timisoara, Timisoara, Romania 28 (a) Faculty of Mathematics, Physics and Informatics, Comenius University, Bratislava; (b) Department of Subnuclear Physics, Institute of Experimental Physics of the Slovak Academy of Sciences, Kosice, Slovak Republic 29 Physics Department, Brookhaven National Laboratory, Upton, NY, United States of America 30 Departamento de Física, Universidad de Buenos Aires, Buenos Aires, Argentina 31 Cavendish Laboratory, University of Cambridge, Cambridge, United Kingdom 32 (a) Department of Physics, University of Cape Town, Cape Town; (b) Department of Mechanical Engineering Science, University of Johannesburg, Johannesburg; (c) School of Physics, University of the Witwatersrand, Johannesburg, South Africa 33 Department of Physics, Carleton University, Ottawa, ON, Canada 34 (a) Faculté des Sciences Ain Chock, Réseau Universitaire de Physique des Hautes Energies – Université Hassan II, Casablanca; (b) Centre National de l’Energie des Sciences Techniques Nucleaires (CNESTEN), Rabat; (c) Faculté des Sciences Semlalia, Université Cadi Ayyad, LPHEA, Marrakech; (d) Faculté des Sciences, Université Mohamed Premier and LPTPM, Oujda; (e) Faculté des sciences, Université Mohammed V, Rabat, Morocco 35 CERN, Geneva, Switzerland 36 Enrico Fermi Institute, University of Chicago, Chicago, IL, United States of America 37 LPC, Université Clermont Auvergne, CNRS/IN2P3, Clermont-Ferrand, France 38 Nevis Laboratory, Columbia University, Irvington, NY, United States of America 39 Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark 40 (a) Dipartimento di Fisica, Università della Calabria, Rende; (b) INFN Gruppo Collegato di Cosenza, Laboratori Nazionali di Frascati, Italy 41 Physics Department, Southern Methodist University, Dallas, TX, United States of America 42 Physics Department, University of Texas at Dallas, Richardson, TX, United States of America 43 (a) Department of Physics, Stockholm University; (b) Oskar Klein Centre, Stockholm, Sweden 44 Deutsches Elektronen-Synchrotron DESY, Hamburg and Zeuthen, Germany 45 Lehrstuhl für Experimentelle Physik IV, Technische Universität Dortmund, Dortmund, Germany 46 Institut für Kern- und Teilchenphysik, Technische Universität Dresden, Dresden, Germany 47 Department of Physics, Duke University, Durham, NC, United States of America 48 SUPA – School of Physics and Astronomy, University of Edinburgh, Edinburgh, United Kingdom 49 INFN e Laboratori Nazionali di Frascati, Frascati, Italy 50 Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany 51 II. Physikalisches Institut, Georg-August-Universität Göttingen, Göttingen, Germany 52 Département de Physique Nucléaire et Corpusculaire, Université de Genève, Genève, Switzerland 53 (a) Dipartimento di Fisica, Università di Genova, Genova; (b) INFN Sezione di Genova, Italy 54 II. Physikalisches Institut, Justus-Liebig-Universität Giessen, Giessen, Germany 55 SUPA – School of Physics and Astronomy, University of Glasgow, Glasgow, United Kingdom 56 LPSC, Université Grenoble Alpes, CNRS/IN2P3, Grenoble INP, Grenoble, France 57 Laboratory for Particle Physics and Cosmology, Harvard University, Cambridge, MA, United States of America 58 (a) Department of Modern Physics and State Key Laboratory of Particle Detection and Electronics, University of Science and Technology of China, Hefei; (b) Institute of Frontier and Interdisciplinary Science and Key Laboratory of Particle Physics and Particle Irradiation (MOE), Shandong University, Qingdao; (c) School of Physics and Astronomy, Shanghai Jiao Tong University, KLPPAC-MoE, SKLPPC, Shanghai; (d) Tsung-Dao Lee Institute, Shanghai, China 59 (a) Kirchhoff-Institut für Physik, Ruprecht-Karls-Universität Heidelberg, Heidelberg; (b) Physikalisches Institut, Ruprecht-Karls-Universität Heidelberg, Heidelberg, Germany 60 Faculty of Applied Information Science, Hiroshima Institute of Technology, Hiroshima, Japan 61 (a) Department of Physics, Chinese University of Hong Kong, Shatin, N.T., Hong Kong; (b) Department of Physics, University of Hong Kong, Hong Kong; (c) Department of Physics and Institute for Advanced Study, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China 62 Department of Physics, National Tsing Hua University, Hsinchu, Taiwan 63 Department of Physics, Indiana University, Bloomington, IN, United States of America 64 (a) INFN Gruppo Collegato di Udine, Sezione di Trieste, Udine; (b) ICTP, Trieste; (c) Dipartimento di Chimica, Fisica e Ambiente, Università di Udine, Udine, Italy 65 (a) INFN Sezione di Lecce; (b) Dipartimento di Matematica e Fisica, Università del Salento, Lecce, Italy 66 (a) INFN Sezione di Milano; (b) Dipartimento di Fisica, Università di Milano, Milano, Italy 67 (a) INFN Sezione di Napoli; (b) Dipartimento di Fisica, Università di Napoli, Napoli, Italy 68 (a) INFN Sezione di Pavia; (b) Dipartimento di Fisica, Università di Pavia, Pavia, Italy 69 (a) INFN Sezione di Pisa; (b) Dipartimento di Fisica E. Fermi, Università di Pisa, Pisa, Italy 70 (a) INFN Sezione di Roma; (b) Dipartimento di Fisica, Sapienza Università di Roma, Roma, Italy 71 (a) INFN Sezione di Roma Tor Vergata; (b) Dipartimento di Fisica, Università di Roma Tor Vergata, Roma, Italy 72 (a) INFN Sezione di Roma Tre; (b) Dipartimento di Matematica e Fisica, Università Roma Tre, Roma, Italy 73 (a) INFN-TIFPA; (b) Università degli Studi di Trento, Trento, Italy 74 Institut für Astro- und Teilchenphysik, Leopold-Franzens-Universität, Innsbruck, Austria 75 University of Iowa, Iowa City, IA, United States of America 76 Department of Physics and Astronomy, Iowa State University, Ames, IA, United States of America 77 Joint Institute for Nuclear Research, Dubna, Russia 78 (a) Departamento de Engenharia Elétrica, Universidade Federal de Juiz de Fora (UFJF), Juiz de Fora; (b) Universidade Federal do Rio De Janeiro COPPE/EE/IF, Rio de Janeiro; (c) Universidade Federal de São João del Rei (UFSJ), São João del Rei; (d) Instituto de Física, Universidade de São Paulo, São Paulo, Brazil 79 KEK, High Energy Accelerator Research Organization, Tsukuba, Japan 80 Graduate School of Science, Kobe University, Kobe, Japan 81 (a) AGH University of Science and Technology, Faculty of Physics and Applied Computer Science, Krakow; (b) Marian Smoluchowski Institute of Physics, Jagiellonian University, Krakow, Poland 82 Institute of Nuclear Physics Polish Academy of Sciences, Krakow, Poland 83 Faculty of Science, Kyoto University, Kyoto, Japan 84 Kyoto University of Education, Kyoto, Japan 518 The ATLAS Collaboration / Physics Letters B 793 (2019) 499–519 85 Research Center for Advanced Particle Physics and Department of Physics, Kyushu University, Fukuoka, Japan 86 Instituto de Física La Plata, Universidad Nacional de La Plata and CONICET, La Plata, Argentina 87 Physics Department, Lancaster University, Lancaster, United Kingdom 88 Oliver Lodge Laboratory, University of Liverpool, Liverpool, United Kingdom 89 Department of Experimental Particle Physics, Jožef Stefan Institute and Department of Physics, University of Ljubljana, Ljubljana, Slovenia 90 School of Physics and Astronomy, Queen Mary University of London, London, United Kingdom 91 Department of Physics, Royal Holloway University of London, Egham, United Kingdom 92 Department of Physics and Astronomy, University College London, London, United Kingdom 93 Louisiana Tech University, Ruston, LA, United States of America 94 Fysiska institutionen, Lunds universitet, Lund, Sweden 95 Centre de Calcul de l’Institut National de Physique Nucléaire et de Physique des Particules (IN2P3), Villeurbanne, France 96 Departamento de Física Teorica C-15 and CIAFF, Universidad Autónoma de Madrid, Madrid, Spain 97 Institut für Physik, Universität Mainz, Mainz, Germany 98 School of Physics and Astronomy, University of Manchester, Manchester, United Kingdom 99 CPPM, Aix-Marseille Université, CNRS/IN2P3, Marseille, France 100 Department of Physics, University of Massachusetts, Amherst, MA, United States of America 101 Department of Physics, McGill University, Montreal, QC, Canada 102 School of Physics, University of Melbourne, Victoria, Australia 103 Department of Physics, University of Michigan, Ann Arbor, MI, United States of America 104 Department of Physics and Astronomy, Michigan State University, East Lansing, MI, United States of America 105 B.I. Stepanov Institute of Physics, National Academy of Sciences of Belarus, Minsk, Belarus 106 Research Institute for Nuclear Problems of Byelorussian State University, Minsk, Belarus 107 Group of Particle Physics, University of Montreal, Montreal, QC, Canada 108 P.N. Lebedev Physical Institute of the Russian Academy of Sciences, Moscow, Russia 109 Institute for Theoretical and Experimental Physics (ITEP), Moscow, Russia 110 National Research Nuclear University MEPhI, Moscow, Russia 111 D.V. Skobeltsyn Institute of Nuclear Physics, M.V. Lomonosov Moscow State University, Moscow, Russia 112 Fakultät für Physik, Ludwig-Maximilians-Universität München, München, Germany 113 Max-Planck-Institut für Physik (Werner-Heisenberg-Institut), München, Germany 114 Nagasaki Institute of Applied Science, Nagasaki, Japan 115 Graduate School of Science and Kobayashi–Maskawa Institute, Nagoya University, Nagoya, Japan 116 Department of Physics and Astronomy, University of New Mexico, Albuquerque, NM, United States of America 117 Institute for Mathematics, Astrophysics and Particle Physics, Radboud University Nijmegen/Nikhef, Nijmegen, Netherlands 118 Nikhef National Institute for Subatomic Physics and University of Amsterdam, Amsterdam, Netherlands 119 Department of Physics, Northern Illinois University, DeKalb, IL, United States of America 120 (a) Budker Institute of Nuclear Physics, SB RAS, Novosibirsk; (b) Novosibirsk State University Novosibirsk, Russia 121 Institute for High Energy Physics of the National Research Centre Kurchatov Institute, Protvino, Russia 122 Department of Physics, New York University, New York, NY, United States of America 123 Ohio State University, Columbus, OH, United States of America 124 Faculty of Science, Okayama University, Okayama, Japan 125 Homer L. Dodge Department of Physics and Astronomy, University of Oklahoma, Norman, OK, United States of America 126 Department of Physics, Oklahoma State University, Stillwater, OK, United States of America 127 Palacký University, RCPTM, Joint Laboratory of Optics, Olomouc, Czech Republic 128 Center for High Energy Physics, University of Oregon, Eugene, OR, United States of America 129 LAL, Université Paris-Sud, CNRS/IN2P3, Université Paris-Saclay, Orsay, France 130 Graduate School of Science, Osaka University, Osaka, Japan 131 Department of Physics, University of Oslo, Oslo, Norway 132 Department of Physics, Oxford University, Oxford, United Kingdom 133 LPNHE, Sorbonne Université, Paris Diderot Sorbonne Paris Cité, CNRS/IN2P3, Paris, France 134 Department of Physics, University of Pennsylvania, Philadelphia, PA, United States of America 135 Konstantinov Nuclear Physics Institute of National Research Centre “Kurchatov Institute”, PNPI, St. Petersburg, Russia 136 Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, PA, United States of America 137 (a) Laboratório de Instrumentação e Física Experimental de Partículas – LIP; (b) Departamento de Física, Faculdade de Ciências, Universidade de Lisboa, Lisboa; (c) Departamento de Física, Universidade de Coimbra, Coimbra; (d) Centro de Física Nuclear da Universidade de Lisboa, Lisboa; (e) Departamento de Física, Universidade do Minho, Braga; (f ) Departamento de Física Teorica y del Cosmos, Universidad de Granada, Granada (Spain); (g) Dep Física and CEFITEC of Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Caparica, Portugal 138 Institute of Physics, Academy of Sciences of the Czech Republic, Prague, Czech Republic 139 Czech Technical University in Prague, Prague, Czech Republic 140 Charles University, Faculty of Mathematics and Physics, Prague, Czech Republic 141 Particle Physics Department, Rutherford Appleton Laboratory, Didcot, United Kingdom 142 IRFU, CEA, Université Paris-Saclay, Gif-sur-Yvette, France 143 Santa Cruz Institute for Particle Physics, University of California Santa Cruz, Santa Cruz, CA, United States of America 144 (a) Departamento de Física, Pontificia Universidad Católica de Chile, Santiago; (b) Departamento de Física, Universidad Técnica Federico Santa María, Valparaíso, Chile 145 Department of Physics, University of Washington, Seattle, WA, United States of America 146 Department of Physics and Astronomy, University of Sheffield, Sheffield, United Kingdom 147 Department of Physics, Shinshu University, Nagano, Japan 148 Department Physik, Universität Siegen, Siegen, Germany 149 Department of Physics, Simon Fraser University, Burnaby, BC, Canada 150 SLAC National Accelerator Laboratory, Stanford, CA, United States of America 151 Physics Department, Royal Institute of Technology, Stockholm, Sweden 152 Departments of Physics and Astronomy, Stony Brook University, Stony Brook, NY, United States of America 153 Department of Physics and Astronomy, University of Sussex, Brighton, United Kingdom 154 School of Physics, University of Sydney, Sydney, Australia 155 Institute of Physics, Academia Sinica, Taipei, Taiwan 156 (a) E. Andronikashvili Institute of Physics, Iv. Javakhishvili Tbilisi State University, Tbilisi; (b) High Energy Physics Institute, Tbilisi State University, Tbilisi, Georgia 157 Department of Physics, Technion, Israel Institute of Technology, Haifa, Israel 158 Raymond and Beverly Sackler School of Physics and Astronomy, Tel Aviv University, Tel Aviv, Israel 159 Department of Physics, Aristotle University of Thessaloniki, Thessaloniki, Greece 160 International Center for Elementary Particle Physics and Department of Physics, University of Tokyo, Tokyo, Japan 161 Graduate School of Science and Technology, Tokyo Metropolitan University, Tokyo, Japan 162 Department of Physics, Tokyo Institute of Technology, Tokyo, Japan The ATLAS Collaboration / Physics Letters B 793 (2019) 499–519 519 163 Tomsk State University, Tomsk, Russia 164 Department of Physics, University of Toronto, Toronto, ON, Canada 165 (a) TRIUMF, Vancouver, BC; (b) Department of Physics and Astronomy, York University, Toronto, ON, Canada 166 Division of Physics and Tomonaga Center for the History of the Universe, Faculty of Pure and Applied Sciences, University of Tsukuba, Tsukuba, Japan 167 Department of Physics and Astronomy, Tufts University, Medford, MA, United States of America 168 Department of Physics and Astronomy, University of California Irvine, Irvine, CA, United States of America 169 Department of Physics and Astronomy, University of Uppsala, Uppsala, Sweden 170 Department of Physics, University of Illinois, Urbana, IL, United States of America 171 Instituto de Física Corpuscular (IFIC), Centro Mixto Universidad de Valencia – CSIC, Valencia, Spain 172 Department of Physics, University of British Columbia, Vancouver, BC, Canada 173 Department of Physics and Astronomy, University of Victoria, Victoria, BC, Canada 174 Fakultät für Physik und Astronomie, Julius-Maximilians-Universität Würzburg, Würzburg, Germany 175 Department of Physics, University of Warwick, Coventry, United Kingdom 176 Waseda University, Tokyo, Japan 177 Department of Particle Physics, Weizmann Institute of Science, Rehovot, Israel 178 Department of Physics, University of Wisconsin, Madison, WI, United States of America 179 Fakultät für Mathematik und Naturwissenschaften, Fachgruppe Physik, Bergische Universität Wuppertal, Wuppertal, Germany 180 Department of Physics, Yale University, New Haven, CT, United States of America 181 Yerevan Physics Institute, Yerevan, Armenia a Also at Borough of Manhattan Community College, City University of New York, NY; United States of America. b Also at California State University, East Bay; United States of America. c Also at Centre for High Performance Computing, CSIR Campus, Rosebank, Cape Town; South Africa. d Also at CERN, Geneva; Switzerland. e Also at CPPM, Aix-Marseille Université, CNRS/IN2P3, Marseille; France. f Also at Département de Physique Nucléaire et Corpusculaire, Université de Genève, Genève; Switzerland. g Also at Departament de Fisica de la Universitat Autonoma de Barcelona, Barcelona; Spain. h Also at Departamento de Física Teorica y del Cosmos, Universidad de Granada, Granada (Spain); Spain. i Also at Department of Applied Physics and Astronomy, University of Sharjah, Sharjah; United Arab Emirates. j Also at Department of Financial and Management Engineering, University of the Aegean, Chios; Greece. k Also at Department of Physics and Astronomy, University of Louisville, Louisville, KY; United States of America. l Also at Department of Physics and Astronomy, University of Sheffield, Sheffield; United Kingdom. m Also at Department of Physics, California State University, Fresno CA; United States of America. n Also at Department of Physics, California State University, Sacramento CA; United States of America. o Also at Department of Physics, King’s College London, London; United Kingdom. p Also at Department of Physics, St. Petersburg State Polytechnical University, St. Petersburg; Russia. q Also at Department of Physics, Stanford University; United States of America. r Also at Department of Physics, University of Fribourg, Fribourg; Switzerland. s Also at Department of Physics, University of Michigan, Ann Arbor MI; United States of America. t Also at Dipartimento di Fisica E. Fermi, Università di Pisa, Pisa; Italy. u Also at Giresun University, Faculty of Engineering, Giresun; Turkey. v Also at Graduate School of Science, Osaka University, Osaka; Japan. w Also at Hellenic Open University, Patras; Greece. x Also at Horia Hulubei National Institute of Physics and Nuclear Engineering, Bucharest; Romania. y Also at II. Physikalisches Institut, Georg-August-Universität Göttingen, Göttingen; Germany. z Also at Institucio Catalana de Recerca i Estudis Avancats, ICREA, Barcelona; Spain. aa Also at Institut für Experimentalphysik, Universität Hamburg, Hamburg; Germany. ab Also at Institute for Mathematics, Astrophysics and Particle Physics, Radboud University Nijmegen/Nikhef, Nijmegen; Netherlands. ac Also at Institute for Particle and Nuclear Physics, Wigner Research Centre for Physics, Budapest; Hungary. ad Also at Institute of Particle Physics (IPP); Canada. ae Also at Institute of Physics, Academia Sinica, Taipei; Taiwan. af Also at Institute of Physics, Azerbaijan Academy of Sciences, Baku; Azerbaijan. ag Also at Institute of Theoretical Physics, Ilia State University, Tbilisi; Georgia. ah Also at Istanbul University, Dept. of Physics, Istanbul; Turkey. ai Also at LAL, Université Paris-Sud, CNRS/IN2P3, Université Paris-Saclay, Orsay; France. aj Also at Louisiana Tech University, Ruston LA; United States of America. ak Also at LPNHE, Sorbonne Université, Paris Diderot Sorbonne Paris Cité, CNRS/IN2P3, Paris; France. al Also at Manhattan College, New York NY; United States of America. am Also at Moscow Institute of Physics and Technology State University, Dolgoprudny; Russia. an Also at National Research Nuclear University MEPhI, Moscow; Russia. ao Also at Near East University, Nicosia, North Cyprus, Mersin; Turkey. ap Also at Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, Freiburg; Germany. aq Also at School of Physics, Sun Yat-sen University, Guangzhou; China. ar Also at The City College of New York, New York NY; United States of America. as Also at The Collaborative Innovation Center of Quantum Matter (CICQM), Beijing; China. at Also at Tomsk State University, Tomsk, and Moscow Institute of Physics and Technology State University, Dolgoprudny; Russia. au Also at TRIUMF, Vancouver BC; Canada. av Also at Universita di Napoli Parthenope, Napoli; Italy. ∗ Deceased.