B. Abbott's research while affiliated with University of Oklahoma and other places

Publications (789)

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The accurate simulation of additional interactions at the ATLAS experiment for the analysis of proton–proton collisions delivered by the Large Hadron Collider presents a significant challenge to the computing resources. During the LHC Run 2 (2015–2018), there were up to 70 inelastic interactions per bunch crossing, which need to be accounted for in...
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The ATLAS experiment at the Large Hadron Collider has a broad physics programme ranging from precision measurements to direct searches for new particles and new interactions, requiring ever larger and ever more accurate datasets of simulated Monte Carlo events. Detector simulation with Geant4 is accurate but requires significant CPU resources. Over...
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A search for long-lived charginos produced either directly or in the cascade decay of heavy prompt gluino states is presented. The search is based on proton–proton collision data collected at a centre-of-mass energy of s = 13 TeV between 2015 and 2018 with the ATLAS detector at the LHC, corresponding to an integrated luminosity of 136 fb-1. Long-li...
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This paper presents studies of Bose–Einstein correlations (BEC) in proton–proton collisions at a centre-of-mass energy of 13 TeV, using data from the ATLAS detector at the CERN Large Hadron Collider. Data were collected in a special low-luminosity configuration with a minimum-bias trigger and a high-multiplicity track trigger, accumulating integrat...
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A bstract A search for decays of pair-produced neutral long-lived particles (LLPs) is presented using 139 fb − 1 of proton-proton collision data collected by the ATLAS detector at the LHC in 2015–2018 at a centre-of-mass energy of 13 TeV. Dedicated techniques were developed for the reconstruction of displaced jets produced by LLPs decaying hadronic...
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A bstract The associated production of a Higgs boson and a top-quark pair is measured in events characterised by the presence of one or two electrons or muons. The Higgs boson decay into a b -quark pair is used. The analysed data, corresponding to an integrated luminosity of 139 fb − 1 , were collected in proton-proton collisions at the Large Hadro...
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A measurement of the energy asymmetry in jet-associated top-quark pair production is presented using 139fb-1 of data collected by the ATLAS detector at the Large Hadron Collider during pp collisions at s=13TeV. The observable measures the different probability of top and antitop quarks to have the higher energy as a function of the jet scattering a...
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This paper presents a measurement of the electroweak production of two jets in association with a Zγ pair, with the Z boson decaying into two neutrinos. It also presents a search for invisible or partially invisible decays of a Higgs boson with a mass of 125 GeV produced through vector-boson fusion with a photon in the final state. These results us...
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During LHC Run 2 (2015–2018) the ATLAS Level-1 topological trigger allowed efficient data-taking by the ATLAS experiment at luminosities up to 2.1×1034 cm-2s-1, which exceeds the design value by a factor of two. The system was installed in 2016 and operated in 2017 and 2018. It uses Field Programmable Gate Array processors to select interesting eve...
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A search for the exotic decay of the Higgs boson (H) into a bb¯ resonance plus missing transverse momentum is described. The search is performed with the ATLAS detector at the Large Hadron Collider using 139 fb−1 of pp collisions at s = 13 TeV. The search targets events from ZH production in an NMSSM scenario where H → χ~20χ~10, with χ~20→aχ~10, wh...
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A technique is presented to measure the efficiency with which c-jets are mistagged as b-jets (mistagging efficiency) using tt¯ events, where one of the W bosons decays into an electron or muon and a neutrino and the other decays into a quark–antiquark pair. The measurement utilises the relatively large and known W→cs branching ratio, which allows a...
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A search for lepton-flavor-violating Z→eτ and Z→μτ decays with pp collision data recorded by the ATLAS detector at the LHC is presented. This analysis uses 139 fb−1 of Run 2 pp collisions at s=13 TeV and is combined with the results of a similar ATLAS search in the final state in which the τ lepton decays hadronically, using the same data set as we...
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A measurement of event-shape variables in proton-proton collisions at large momentum transfer is presented using data collected at s = 13 TeV with the ATLAS detector at the Large Hadron Collider. Six event-shape variables calculated using hadronic jets are studied in inclusive multijet events using data corresponding to an integrated luminosity of...
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A search for chargino–neutralino pair production in three-lepton final states with missing transverse momentum is presented. The study is based on a dataset of s√=13 TeV pp collisions recorded with the ATLAS detector at the LHC, corresponding to an integrated luminosity of 139 fb−1. No significant excess relative to the Standard Model predictions i...
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The fragmentation properties of jets containing b-hadrons are studied using charged B mesons in 139 fb−1 of pp collisions at s = 13 TeV, recorded with the ATLAS detector at the LHC during the period from 2015 to 2018. The B mesons are reconstructed using the decay of B± into J/ψK±, with the J/ψ decaying into a pair of muons. Jets are reconstructed...
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The production of dark matter in association with Higgs bosons is predicted in several extensions of the Standard Model. An exploration of such scenarios is presented, considering final states with missing transverse momentum and b-tagged jets consistent with a Higgs boson. The analysis uses proton-proton collision data at a centre-of-mass energy o...
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We describe an analysis comparing the pp¯ elastic cross section as measured by the D0 Collaboration at a center-of-mass energy of 1.96 TeV to that in pp collisions as measured by the TOTEM Collaboration at 2.76, 7, 8, and 13 TeV using a model-independent approach. The TOTEM cross sections, extrapolated to a center-of-mass energy of s=1.96 TeV, are...
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Measurements of both the inclusive and differential production cross sections of a top-quark–antiquark pair in association with a Z boson (tt¯Z) are presented. The measurements are performed by targeting final states with three or four isolated leptons (electrons or muons) and are based on s=13 TeV proton–proton collision data with an integrated lu...
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Non-ionizing energy loss causes bulk damage to the silicon sensors of the ATLAS pixel and strip detectors. This damage has important implications for data-taking operations, charged-particle track reconstruction, detector simulations, and physics analysis. This paper presents simulations and measurements of the leakage current in the ATLAS pixel de...
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Measurements of four-lepton differential and integrated fiducial cross-sections in events with two same-flavour, opposite-charge electron or muon pairs are presented. The data correspond to 139 fb−1 of s = 13 TeV proton-proton collisions, collected by the ATLAS detector during Run 2 of the Large Hadron Collider (2015–2018). The final state has cont...
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The results of a search for gluino and squark pair production with the pairs decaying via the lightest charginos into a final state consisting of two W bosons, the lightest neutralinos (χ~10), and quarks, are presented: the signal is characterised by the presence of a single charged lepton (e± or μ±) from a W boson decay, jets, and missing transver...
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This article presents a new set of proton parton distribution functions, ATLASepWZVjet20, produced in an analysis at next-to-next-to-leading order in QCD. The new data sets considered are the measurements of W+ and W− boson and Z boson production in association with jets in pp collisions at s = 8 TeV performed by the ATLAS experiment at the LHC wit...
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A search for pair production of third-generation scalar leptoquarks decaying into a top quark and a τ-lepton is presented. The search is based on a dataset of pp collisions at s = 13 TeV recorded with the ATLAS detector during Run 2 of the Large Hadron Collider, corresponding to an integrated luminosity of 139 fb−1. Events are selected if they have...
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A search for charged Higgs bosons decaying into a top quark and a bottom quark is presented. The data analysed correspond to 139 fb−1 of proton-proton collisions at s = 13 TeV, recorded with the ATLAS detector at the LHC. The production of a heavy charged Higgs boson in association with a top quark and a bottom quark, pp → tbH+ → tbtb, is explored...
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A search for charged Higgs bosons decaying into W±W± or W±Z bosons is performed, involving experimental signatures with two leptons of the same charge, or three or four leptons with a variety of charge combinations, missing transverse momentum and jets. A data sample of proton-proton collisions at a centre-of-mass energy of 13 TeV recorded with the...
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A search for the Higgs boson decaying into a photon and a pair of electrons or muons with an invariant mass mℓℓ<30 GeV is presented. The analysis is performed using 139 fb⁻¹ of proton–proton collision data, produced by the LHC at a centre-of-mass energy of 13 TeV and collected by the ATLAS experiment. Evidence for the H→ℓℓγ process is found with a...
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The results of a search for direct pair production of top squarks and for dark matter in events with two opposite-charge leptons (electrons or muons), jets and missing transverse momentum are reported, using 139 fb−1 of integrated luminosity from proton-proton collisions at s√ = 13 TeV, collected by the ATLAS detector at the Large Hadron Collider d...
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A search for new phenomena with top quark pairs in final states with one isolated electron or muon, multiple jets, and large missing transverse momentum is performed. Signal regions are designed to search for two-, three-, and four-body decays of the directly pair-produced supersymmetric partner of the top quark (stop). Additional signal regions ar...
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A measurement of the B0s→J/ψϕ decay parameters using 80.5fb−1 of integrated luminosity collected with the ATLAS detector from 13 TeV proton–proton collisions at the LHC is presented. The measured parameters include the CP-violating phase ϕs, the width difference ΔΓs between the B0s meson mass eigenstates and the average decay width Γs. The values m...
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The Lagrangian in eq. (2.1) of JHEP11 (2020) 005 has an erroneous factor of 1/2. The analysis code used for the results reported in the paper does not have this factor. The results remain unchanged.
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Several extensions of the Standard Model predict the production of dark matter particles at the LHC. An uncharted signature of dark matter particles produced in association with VV=W±W∓ or ZZ pairs from a decay of a dark Higgs boson s is searched for using 139 fb−1 of pp collisions recorded by the ATLAS detector at a center-of-mass energy of 13 TeV...
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This paper describes a measurement of light-by-light scattering based on Pb+Pb collision data recorded by the ATLAS experiment during Run 2 of the LHC. The study uses 2.2 nb⁻¹ of integrated luminosity collected in 2015 and 2018 at sNN = 5.02 TeV. Light-by-light scattering candidates are selected in events with two photons produced exclusively, each...
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The first measurement of longitudinal decorrelations of harmonic flow amplitudes vn for n=2–4 in Xe+Xe collisions at sNN=5.44 TeV is obtained using 3 μb−1 of data with the ATLAS detector at the LHC. The decorrelation signal for v3 and v4 is found to be nearly independent of collision centrality and transverse momentum (pT) requirements on final-sta...
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A search is presented for the production of the Standard Model Higgs boson in association with a high-energy photon. With a focus on the vector-boson fusion process and the dominant Higgs boson decay into b-quark pairs, the search benefits from a large reduction of multijet background compared to more inclusive searches. Results are reported from t...
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Measurements of the Standard Model Higgs boson decaying into a bb¯ pair and produced in association with a W or Z boson decaying into leptons, using proton–proton collision data collected between 2015 and 2018 by the ATLAS detector, are presented. The measurements use collisions produced by the Large Hadron Collider at a centre-of-mass energy of s=...
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The yield of charged particles opposite to a Z boson with large transverse momentum (pT) is measured in 260 pb−1 of pp and 1.7 nb−1 of Pb+Pb collision data at 5.02 TeV per nucleon pair recorded with the ATLAS detector at the Large Hadron Collider. The Z boson tag is used to select hard-scattered partons with specific kinematics, and to observe how...
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The integrated fiducial cross-section and unfolded differential jet mass spectrum of high transverse momentum Z→bb‾ decays are measured in Zγ events in proton–proton collisions at s=13TeV. The data analysed were collected between 2015 and 2016 with the ATLAS detector at the Large Hadron Collider and correspond to an integrated luminosity of 36.1fb−...
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A search for the dimuon decay of the Standard Model (SM) Higgs boson is performed using data corresponding to an integrated luminosity of 139 fb−1 collected with the ATLAS detector in Run 2 pp collisions at s=13 TeV at the Large Hadron Collider. The observed (expected) significance over the background-only hypothesis for a Higgs boson with a mass o...
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One correction is noted for the paper. A wrong cross-section was used for the theory prediction in figure 6 due to not taking into account the VHH contamination properly in the rescaling formula for the signal samples.
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A search for a heavy neutral Higgs boson, A, decaying into a Z boson and another heavy Higgs boson, H, is performed using a data sample corresponding to an integrated luminosity of 139 fb−1 from proton–proton collisions at s√=13 TeV recorded by the ATLAS detector at the LHC. The search considers the Z boson decaying into electrons or muons and the...
Article
Jet substructure has provided new opportunities for searches and measurements at the LHC, and has seen continuous development since the optimization of the large-radius jet definition used by ATLAS was performed during Run 1. A range of new inputs to jet reconstruction, pile-up mitigation techniques and jet grooming algorithms motivate an optimisat...
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A search for pair production of scalar leptoquarks, each decaying into either an electron or a muon and a top quark, is presented. This is the first leptoquark search using ATLAS data to investigate top-philic cross-generational couplings that could provide explanations for recently observed anomalies in B meson decays. This analysis targets high l...
Article
A search for heavy resonances decaying into a pair of Z bosons leading to \ell ^+\ell ^-\ell '^+\ell '^- and \ell ^+\ell ^-\nu {{\bar{\nu }}} final states, where \ell stands for either an electron or a muon, is presented. The search uses proton–proton collision data at a centre-of-mass energy of 13 TeV collected from 2015 to 2018 that corresponds t...
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The observation of forward proton scattering in association with lepton pairs (e+e−+p or μ+μ−+p) produced via photon fusion is presented. The scattered proton is detected by the ATLAS Forward Proton spectrometer, while the leptons are reconstructed by the central ATLAS detector. Proton-proton collision data recorded in 2017 at a center-of-mass ener...
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This Letter presents a search for the production of new heavy resonances decaying into a Higgs boson and a photon using proton-proton collision data at s=13 TeV collected by the ATLAS detector at the LHC. The data correspond to an integrated luminosity of 139 fb−1. The analysis is performed by reconstructing hadronically decaying Higgs boson (H→bb¯...
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This paper reports on a search for heavy resonances decaying into WW, ZZ or WZ using proton–proton collision data at a centre-of-mass energy of s=13 TeV. The data, corresponding to an integrated luminosity of 139 fb1, were recorded with the ATLAS detector from 2015 to 2018 at the Large Hadron Collider. The search is performed for final states in wh...
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The jet energy scale, jet energy resolution, and their systematic uncertainties are measured for jets reconstructed with the ATLAS detector in 2012 using proton–proton data produced at a centre-of-mass energy of 8 TeV with an integrated luminosity of 20fb-1. Jets are reconstructed from clusters of energy depositions in the ATLAS calorimeters using...
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A search for Higgs boson decays into a Z boson and a light resonance in two-lepton plus jet events is performed, using a pp collision dataset with an integrated luminosity of 139 fb−1 collected at s=13 TeV by the ATLAS experiment at the CERN LHC. The resonance considered is a light boson with a mass below 4 GeV from a possible extended scalar secto...
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The top anti-top quark production cross-section is measured in the lepton+jets channel using proton– proton collision data at a centre-of-mass energy of √s = 13 TeV collected with the ATLAS detector at the LHC. The dataset corresponds to an integrated luminosity of 139 fb−1. Events with exactly one charged lepton and four or more jets in the final...
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2020 IOP Publishing. The PreProcessor of the ATLAS Level-1 Calorimeter Trigger prepares the analogue trigger signals sent from the ATLAS calorimeters by digitising, synchronising, and calibrating them to reconstruct transverse energy deposits, which are then used in further processing to identify event features. During the first long shutdown of th...
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In this paper, a new technique for reconstructing and identifying hadronically decaying τ+τ− pairs with a large Lorentz boost, referred to as the di-τ tagger, is developed and used for the first time in the ATLAS experiment at the Large Hadron Collider. A benchmark di-τ tagging selection is employed in the search for resonant Higgs boson pair produ...
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Inclusive and differential fiducial cross sections of the Higgs boson are measured in the H → Z Z∗ → 4 ( = e, μ) decay channel. The results are based on protonproton collision data produced at the Large Hadron Collider at a centre-of-mass energy of 13 TeV and recorded by the ATLAS detector from 2015 to 2018, equivalent to an integrated luminosity o...
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A search for the Zγ decay of the Higgs boson, with Z boson decays into pairs of electrons or muons is presented. The analysis uses proton–proton collision data at √s = 13 TeV corresponding to an integrated luminosity of 139 fb^{-1} recorded by the ATLAS detector at the Large Hadron Collider. The observed data are consistent with the expected backgr...
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Two additions impacting tables 3 and 4 in ref. [1] are presented in the following. No significant impact is found for other results or figures in ref. [1].
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A bstract A search for a chargino-neutralino pair decaying via the 125 GeV Higgs boson into photons is presented. The study is based on the data collected between 2015 and 2018 with the ATLAS detector at the LHC, corresponding to an integrated luminosity of 139 fb − 1 of pp collisions at a centre-of-mass energy of 13 TeV. No significant excess over...
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A bstract Results of a search for new particles decaying into eight or more jets and moderate missing transverse momentum are presented. The analysis uses 139 fb − 1 of proton-proton collision data at $$ \sqrt{s} $$ s = 13 TeV collected by the ATLAS experiment at the Large Hadron Collider between 2015 and 2018. The selection rejects events containi...
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This paper presents a search for new heavy particles decaying into a pair of top quarks using 139 fb−1 of proton-proton collision data recorded at a centre-of-mass energy of s = 13 TeV with the ATLAS detector at the Large Hadron Collider. The search is performed using events consistent with pair production of high-transverse-momentum top quarks and...
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Figure 5b of the paper [1] contained a misinterpretation in the comparison between the reported new ATLAS measurement of the process pp → Xp and previously published CMS data [2]. The ATLAS measurement corresponds to cases where either proton dissociates.
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A bstract Inclusive and differential cross-sections for the production of top quarks in association with a photon are measured with proton-proton collision data corresponding to an integrated luminosity of 139 fb − 1 . The data were collected by the ATLAS detector at the LHC during Run 2 between 2015 and 2018 at a centre-of-mass energy of 13 TeV. T...
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The results of a search for electroweakino pair production \(pp \rightarrow \tilde{\chi }^\pm _1 \tilde{\chi }^0_2\) in which the chargino (\(\tilde{\chi }^\pm _1\)) decays into a W boson and the lightest neutralino (\(\tilde{\chi }^0_1\)), while the heavier neutralino (\(\tilde{\chi }^0_2\)) decays into the Standard Model 125 GeV Higgs boson and a...
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A bstract The factor of four increase in the LHC luminosity, from 0 . 5 × 10 ³⁴ cm − 2 s − 1 to 2 . 0 × 10 ³⁴ cm − 2 s − 1 , and the corresponding increase in pile-up collisions during the 2015–2018 data-taking period, presented a challenge for the ATLAS trigger, particularly for those algorithms that select events with missing transverse momentum....