Browsing by Author "Abbott, D.C."

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Citation - WoS: 6
Citation - Scopus: 4
The Atlas Fast Tracker System
(IOP Publishing Ltd, 2021) Aad, G.; Abbott, B.; Abbott, D.C.; Abud, A.A.; Abeling, K.; Abhayasinghe, D.K.; Sultansoy, Saleh; The ATLAS Collaboration
The ATLAS Fast TracKer (FTK) was designed to provide full tracking for the ATLAS high-level trigger by using pattern recognition based on Associative Memory (AM) chips and fitting in high-speed field programmable gate arrays. The tracks found by the FTK are based on inputs from all modules of the pixel and silicon microstrip trackers. The as-built FTK system and components are described, as is the online software used to control them while running in the ATLAS data acquisition system. Also described is the simulation of the FTK hardware and the optimization of the AM pattern banks. An optimization for long-lived particles with large impact parameter values is included. A test of the FTK system with the data playback facility that allowed the FTK to be commissioned during the shutdown between Run 2 and Run 3 of the LHC is reported. The resulting tracks from part of the FTK system covering a limited ?-? region of the detector are compared with the output from the FTK simulation. It is shown that FTK performance is in good agreement with the simulation. © The ATLAS collaboration
Citation - Scopus: 1
Author Correction: a Detailed Map of Higgs Boson Interactions by the Atlas Experiment Ten Years After the Discovery (nature, (2022), 607, 7917, (52-59), 10.1038/S41586-022-04893-w)
(Nature Research, 2023) Aad, G.; Abbott, B.; Abbott, D.C.; Abeling, K.; Abidi, S.H.; Aboulhorma, A.; Abramowicz, H.
Correction to: Nature Published online 4 July 2022 In the version of this article initially published, the ATLAS Collaboration author names, affiliations and acknowledgements were omitted and have now been included in the HTML and PDF versions of the article. © 2023, The Author(s).
Citation - WoS: 42
Citation - Scopus: 59
Calibration of the Light-Flavour Jet Mistagging Efficiency of the B-Tagging Algorithms With Z+jets Events Using 139 Fb - 1 of Atlas Proton–proton Collision Data at √s=13 Tev
(Institute for Ionics, 2023) Aad, G.; Abbott, B.; Abbott, D.C.; Abeling, K.; Abidi, S.H.; Aboulhorma, A.; Abramowicz, H.
The identification of b-jets, referred to as b-tagging, is an important part of many physics analyses in the ATLAS experiment at the Large Hadron Collider and an accurate calibration of its performance is essential for high-quality physics results. This publication describes the calibration of the light-flavour jet mistagging efficiency in a data sample of proton–proton collision events at s=13 TeV corresponding to an integrated luminosity of 139 fb - 1 . The calibration is performed in a sample of Z bosons produced in association with jets. Due to the low mistagging efficiency for light-flavour jets, a method which uses modified versions of the b-tagging algorithms referred to as flip taggers is used in this work. A fit to the jet-flavour-sensitive secondary-vertex mass is performed to extract a scale factor from data, to correct the light-flavour jet mistagging efficiency in Monte Carlo simulations, while simultaneously correcting the b-jet efficiency. With this procedure, uncertainties coming from the modeling of jets from heavy-flavour hadrons are considerably lower than in previous calibrations of the mistagging scale factors, where they were dominant. The scale factors obtained in this calibration are consistent with unity within uncertainties. © 2023, The Author(s).
Citation - WoS: 19
Citation - Scopus: 22
Constraints on Higgs Boson Production With Large Transverse Momentum Using H -> B(b)over-Bar Decays in the Atlas Detector
(Amer Physical Soc, 2022) Aad, G.; Abbott, B.; Abbott, D.C.; Abud, A. Abed; Abeling, K.; Abhayasinghe D.K.; The ATLAS Collaboration; Sultansoy, Saleh
This paper reports constraints on Higgs boson production with transverse momentum above 1 TeV. The analyzed data from proton-proton collisions at a center-of-mass energy of 13 TeV were recorded with the ATLAS detector at the Large Hadron Collider from 2015 to 2018 and correspond to an integrated luminosity of 136 fb(-1.) Higgs bosons decaying into b (b) over bar are reconstructed as single large-radius jets recoiling against a hadronic system and are identified by the experimental signature of two b-hadron decays. The experimental techniques are validated in the same kinematic regime using the Z -> b (b) over bar process. The 95% confidence-level upper limit on the cross section for Higgs boson production with transverse momentum above 450 GeV is 115 fb, and above 1 TeV it is 9.6 fb. The Standard Model cross section predictions for a Higgs boson with a mass of 125 GeV in the same kinematic regions are 18.4 fb and 0.13 fb, respectively.
Citation - WoS: 7
Citation - Scopus: 19
Constraints on Higgs Boson Properties Using Ww*(-> E Nu Mu Nu)jj Production in 36.1 Fb(-1) of Root S=13 Tev Pp Collisions With the Atlas Detector
(Springer, 2022) Aad, G.; Abbott, B.; Abbott, D.C.; Abud, A. Abed; Abeling, K.; Abhayasinghe D.K.; The ATLAS Collaboration; Sultansoy, Saleh
This article presents the results of two studies of Higgs boson properties using the WW*(-> e nu mu nu)jj final state, based on a dataset corresponding to 36.1fb(-1) of root s = 13 TeV proton-proton collisions recorded by the ATLAS experiment at the Large Hadron Collider. The first study targets Higgs boson production via gluon-gluon fusion and constrains the CP properties of the effective Higgs-gluon interaction. Using angular distributions and the overall rate, a value of tan (alpha) = 0.0 +/- 0.4(stat.) +/- 0.3(syst.) is obtained for the tangent of the mixing angle for CP-even and CP-odd contributions. The second study exploits the vector-boson fusion production mechanism to probe the Higgs boson couplings to longitudinally and transversely polarised W and Z bosons in both the production and the decay of the Higgs boson; these couplings have not been directly constrained previously. The polarisation-dependent coupling-strength scale factors are defined as the ratios of the measured polarisation-dependent coupling strengths to those predicted by the Standard Model, and are determined using rate and kinematic information to be a(L) = 0.91(-0.18)(+0.10)(stat.)(-0.17)(+0.09)(syst.) and a(T) = 1.2 +/- 0.4(stat.)(-0.3)(+0.2)(syst.). These coupling strengths are translated into pseudo-observables, resulting in kappa(VV) = 0.91(-0.18)(+0.10)(stat.)(-0.17)(+0.09)(syst.) and epsilon(VV) = 0.13(-0.20)(+0.28)(stat.)(-0.10)(+0.08)(syst.). All results are consistent with the Standard Model predictions.
Citation - WoS: 16
Citation - Scopus: 16
Constraints on Spin-0 Dark Matter Mediators and Invisible Higgs Decays Using Atlas 13 Tev Pp Collision Data With Two Top Quarks and Missing Transverse Momentum in the Final State
(Institute for Ionics, 2023) Aad, G.; Abbott, B.; Abbott, D.C.; Abeling, K.; Abidi, S.H.; Aboulhorma, A.; Abramowicz, H.
This paper presents a statistical combination of searches targeting final states with two top quarks and invisible particles, characterised by the presence of zero, one or two leptons, at least one jet originating from a b-quark and missing transverse momentum. The analyses are searches for phenomena beyond the Standard Model consistent with the direct production of dark matter in pp collisions at the LHC, using 139 fb - 1 of data collected with the ATLAS detector at a centre-of-mass energy of 13 TeV. The results are interpreted in terms of simplified dark matter models with a spin-0 scalar or pseudoscalar mediator particle. In addition, the results are interpreted in terms of upper limits on the Higgs boson invisible branching ratio, where the Higgs boson is produced according to the Standard Model in association with a pair of top quarks. For scalar (pseudoscalar) dark matter models, with all couplings set to unity, the statistical combination extends the mass range excluded by the best of the individual channels by 50 (25) GeV, excluding mediator masses up to 370 GeV. In addition, the statistical combination improves the expected coupling exclusion reach by 14% (24%), assuming a scalar (pseudoscalar) mediator mass of 10 GeV. An upper limit on the Higgs boson invisible branching ratio of 0.38 (0.30-0.09+0.13) is observed (expected) at 95% confidence level. © 2023, The Author(s).
Citation - WoS: 2
Citation - Scopus: 11
Cross-Section Measurements for the Production of a Z Boson in Association With High-Transverse Jets in Pp Collisions at ?s = 13 Tev With the Atlas Detector
(Springer Science and Business Media Deutschland GmbH, 2023) Aad, G.; Abbott, B.; Abbott, D.C.; Abeling, K.; Abidi, S.H.; Aboulhorma, A.; Abramowicz, H.
Cross-section measurements for a Z boson produced in association with high-transverse-momentum jets (p T ? 100 GeV) and decaying into a charged-lepton pair (e + e ? , ? + ? ?) are presented. The measurements are performed using proton–proton collisions at s = 13 TeV corresponding to an integrated luminosity of 139 fb?1 collected by the ATLAS experiment at the LHC. Measurements of angular correlations between the Z boson and the closest jet are performed in events with at least one jet with p T ? 500 GeV. Event topologies of particular interest are the collinear emission of a Z boson in dijet events and a boosted Z boson recoiling against a jet. Fiducial cross sections are compared with state-of-the-art theoretical predictions. The data are found to agree with next-to-next-to-leading-order predictions by NNLOjet and with the next-to-leading-order multi-leg generators MadGraph5_aMC@NLO and Sherpa. [Figure not available: see fulltext.]. © 2023, The Author(s).
Citation - Scopus: 18
Deep Generative Models for Fast Photon Shower Simulation in Atlas
(Springer Nature, 2024) Aad, G.; Abbott, B.; Abbott, D.C.; Abud, A.A.; Abeling, K.; Abhayasinghe, D.K.; Abidi, S.H.
The need for large-scale production of highly accurate simulated event samples for the extensive physics programme of the ATLAS experiment at the Large Hadron Collider motivates the development of new simulation techniques. Building on the recent success of deep learning algorithms, variational autoencoders and generative adversarial networks are investigated for modelling the response of the central region of the ATLAS electromagnetic calorimeter to photons of various energies. The properties of synthesised showers are compared with showers from a full detector simulation using geant4. Both variational autoencoders and generative adversarial networks are capable of quickly simulating electromagnetic showers with correct total energies and stochasticity, though the modelling of some shower shape distributions requires more refinement. This feasibility study demonstrates the potential of using such algorithms for ATLAS fast calorimeter simulation in the future and shows a possible way to complement current simulation techniques. © The Author(s) 2024.
Citation - WoS: 316
Citation - Scopus: 381
A Detailed Map of Higgs Boson Interactions by the Atlas Experiment Ten Years After the Discovery
(Nature Research, 2022) Aad, G.; Abbott, B.; Abbott, D.C.; Abeling, K.; Abidi, S.H.; Aboulhorma, A.; Abramowicz, H.
The standard model of particle physics1–4 describes the known fundamental particles and forces that make up our Universe, with the exception of gravity. One of the central features of the standard model is a field that permeates all of space and interacts with fundamental particles5–9. The quantum excitation of this field, known as the Higgs field, manifests itself as the Higgs boson, the only fundamental particle with no spin. In 2012, a particle with properties consistent with the Higgs boson of the standard model was observed by the ATLAS and CMS experiments at the Large Hadron Collider at CERN10,11. Since then, more than 30 times as many Higgs bosons have been recorded by the ATLAS experiment, enabling much more precise measurements and new tests of the theory. Here, on the basis of this larger dataset, we combine an unprecedented number of production and decay processes of the Higgs boson to scrutinize its interactions with elementary particles. Interactions with gluons, photons, and W and Z bosons—the carriers of the strong, electromagnetic and weak forces—are studied in detail. Interactions with three third-generation matter particles (bottom (b) and top (t) quarks, and tau leptons (τ)) are well measured and indications of interactions with a second-generation particle (muons, μ) are emerging. These tests reveal that the Higgs boson discovered ten years ago is remarkably consistent with the predictions of the theory and provide stringent constraints on many models of new phenomena beyond the standard model. © 2022, The Author(s).
Citation - Scopus: 12
Differential Tt¯ Cross-Section Measurements Using Boosted Top Quarks in the All-Hadronic Final State With 139 Fb?1 of Atlas Data
(Springer Science and Business Media Deutschland GmbH, 2023) Aad, G.; Abbott, B.; Abbott, D.C.; Abed, Abud, A.; Abeling, K.; Abhayasinghe, D.K.; Abidi, S.H.
Measurements of single-, double-, and triple-differential cross-sections are presented for boosted top-quark pair-production in 13 TeV proton–proton collisions recorded by the ATLAS detector at the LHC. The top quarks are observed through their hadronic decay and reconstructed as large-radius jets with the leading jet having transverse momentum (pT) greater than 500 GeV. The observed data are unfolded to remove detector effects. The particle-level cross-section, multiplied by the tt¯ ? WWbb¯ branching fraction and measured in a fiducial phase space defined by requiring the leading and second-leading jets to have pT> 500 GeV and pT> 350 GeV, respectively, is 331 ± 3(stat.) ± 39(syst.) fb. This is approximately 20% lower than the prediction of 398?49+48 fb by Powheg+Pythia 8 with next-to-leading-order (NLO) accuracy but consistent within the theoretical uncertainties. Results are also presented at the parton level, where the effects of top-quark decay, parton showering, and hadronization are removed such that they can be compared with fixed-order next-to-next-to-leading-order (NNLO) calculations. The parton-level cross-section, measured in a fiducial phase space similar to that at particle level, is 1.94 ± 0.02(stat.) ± 0.25(syst.) pb. This agrees with the NNLO prediction of 1.96?0.17+0.02 pb. Reasonable agreement with the differential cross-sections is found for most NLO models, while the NNLO calculations are generally in better agreement with the data. The differential cross-sections are interpreted using a Standard Model effective field-theory formalism and limits are set on Wilson coefficients of several four-fermion operators. [Figure not available: see fulltext.]. © 2023, The Author(s).
Citation - WoS: 64
Citation - Scopus: 55
Direct Constraint on the Higgs-Charm Coupling From a Search for Higgs Boson Decays Into Charm Quarks With the Atlas Detector
(Springer, 2022) Aad, G.; Abbott, B.; Abbott, D.C.; Abud, A. Abed; Abeling, K.; Abhayasinghe D.K.; The ATLAS Collaboration; Sultansoy, Saleh
A search for the Higgs boson decaying into a pair of charm quarks is presented. The analysis uses proton- proton collisions to target the production of a Higgs boson in association with a leptonically decaying W or Z boson. The dataset delivered by the LHC at a centre-of-mass energy of root s = 13 TeV and recorded by the ATLAS detector corresponds to an integrated luminosity of 139 fb(-1). Flavour-tagging algorithms are used to identify jets originating from the hadronisation of charm quarks. The analysis method is validated with the simultaneous measurement of WW, WZ and ZZ production, with observed (expected) significances of 2.6 (2.2) standard deviations above the background-only prediction for the (W/Z)Z(-> c (c) over bar) process and 3.8 (4.6) standard deviations for the (W/Z)W(-> cq) process. The (WIZ)H(-> c (c) over bar) search yields an observed (expected) upper limit of 26 (31) times the predicted Standard Model crosssection times branching fraction for a Higgs boson with a mass of 125 GeV, corresponding to an observed (expected) constraint on the charm Yukawa coupling modifier vertical bar k(c)vertical bar < 8.5 (12.4), at the 95% confidence level. A combination with the ATLAS (W/Z)H, H -> b<(b)over bar> analysis is performed, allowing the ratio k(c)/k(b) to be constrained to less than 4.5 at the 95% confidence level, smaller than the ratio of the b- and c-quark masses, and therefore determines the Higgs-charm coupling to be weaker than the Higgs-bottom coupling at the 95% confidence level.
Citation - WoS: 11
Citation - Scopus: 11
Erratum To: Higgs Boson Production Cross-Section Measurements and Their Eft Interpretation in the 4 ? Decay Channel at S = 13 Tev With the Atlas Detector (the European Physical Journal C, (2020), 80, 10, (957), 10.1140/Epjc
(Springer Science and Business Media Deutschland GmbH, 2021) Aad, G.; Abbott, B.; Abbott, D.C.; Abud, A.A.; Abeling, K.; Abhayasinghe, D.K.; Sultansoy, Saleh; The ATLAS Collaboration
When quoting the final cross section result in the text of the paper (Eur. Phys. J. C 80 (2020) 957), the theory component of the uncertainty was incorrectly set to 0.04 pb while the correct value of 0.03 pb was given in Table 8 and in all other results reported in this paper. © 2021, CERN for the benefit of the ATLAS collaboration.
Citation - WoS: 32
Citation - Scopus: 23
Erratum To: Measurement of Light-By Scattering and Search for Axion-Like Particles With 2.2 Nb?1 of Pb+pb Data With the Atlas Detector (journal of High Energy Physics, (2021), 2021, 3, (243), 10.1007/Jhep03(2021)243)
(Springer Science and Business Media Deutschland GmbH, 2021) Aad, G.; Abbott, B.; Abbott, D.C.; Abed Abud, A.; Abeling, K.; Abhayasinghe, D.K.; Sultansoy, Saleh; The ATLAS Collaboration
One correction is noted for the paper, which does not affect the results reported. The right panel of figure 9 is corrected as it contained the “internal” label, giving the misleading impression on the credibility of the figure. © 2021, The Author(s).
Citation - WoS: 6
Erratum To: Search for Phenomena Beyond the Standard Model in Events With Large B-Jet Multiplicity Using the Atlas Detector at the Lhc (the European Physical Journal C, (2021), 81, 1, (11), 10.1140/Epjc
(Springer Science and Business Media Deutschland GmbH, 2021) Aad, G.; Abbott, B.; Abbott, D.C.; Abud, A.A.; Abeling, K.; Abhayasinghe, D.K.; Sultansoy, Saleh; The ATLAS Collaboration
In the original HTML version of this article, one affiliation of the author V. O. Tikhomirov was missing. He is affiliated to the following two affiliations: P.N. Lebedev Physical Institute of the Russian Academy of Sciences, Moscow, Russia National Research Nuclear University MEPhI, Moscow, Russia The original article has been corrected. © 2021, CERN for the benefit of the ATLAS collaboration.
Citation - WoS: 15
Citation - Scopus: 8
Erratum To: Search for the Hh ? Bb¯ Bb¯ Process Via Vector-Boson Fusion Production Using Proton-Proton Collisions at S = 13 Tev With the Atlas Detector (journal of High Energy Physics, (2020), 2020, 7, (108), 10.1007/Jhep07(2020)108)
(Springer Science and Business Media Deutschland GmbH, 2021) Aad, G.; Abbott, B.; Abbott, D.C.; Abed Abud, A.; Abeling, K.; Abhayasinghe, D.K.; Sultansoy, Saleh; The ATLAS Collaboration
One correction is noted for the paper. © 2021, The Author(s).
Citation - WoS: 8
Citation - Scopus: 8
Evidence for the Charge Asymmetry in (formula Presented.) Production at √s = 13 Tev With the Atlas Detector
(Springer Science and Business Media Deutschland GmbH, 2023) Aad, G.; Abbott, B.; Abbott, D.C.; Abeling, K.; Abidi, S.H.; Aboulhorma, A.; Abramowicz, H.
Inclusive and differential measurements of the top–antitop (Formula presented.) charge asymmetry (Formula presented.) and the leptonic asymmetry (Formula presented.) are presented in proton–proton collisions at s = 13 TeV recorded by the ATLAS experiment at the CERN Large Hadron Collider. The measurement uses the complete Run 2 dataset, corresponding to an integrated luminosity of 139 fb−1, combines data in the single-lepton and dilepton channels, and employs reconstruction techniques adapted to both the resolved and boosted topologies. A Bayesian unfolding procedure is performed to correct for detector resolution and acceptance effects. The combined inclusive (Formula presented.) charge asymmetry is measured to be (Formula presented.), which differs from zero by 4.7 standard deviations. Differential measurements are performed as a function of the invariant mass, transverse momentum and longitudinal boost of the (Formula presented.) system. Both the inclusive and differential measurements are found to be compatible with the Standard Model predictions, at next-to-next-to-leading order in quantum chromodynamics perturbation theory with next-to-leading-order electroweak corrections. The measurements are interpreted in the framework of the Standard Model effective field theory, placing competitive bounds on several Wilson coefficients. [Figure not available: see fulltext.]. © 2023, The Author(s).
Citation - WoS: 9
Citation - Scopus: 14
Exclusive Dielectron Production in Ultraperipheral Pb+pb Collisions at √snn = 5.02 Tev With Atlas
(Springer Science and Business Media Deutschland GmbH, 2023) Aad, G.; Abbott, B.; Abbott, D.C.; Abeling, K.; Abidi, S.H.; Aboulhorma, A.; Abramowicz, H.
Exclusive production of dielectron pairs, γγ → e + e −, is studied using Lint = 1.72 nb−1 of data from ultraperipheral collisions of lead nuclei at sNN = 5.02 TeV recorded by the ATLAS detector at the LHC. The process of interest proceeds via photon–photon interactions in the strong electromagnetic fields of relativistic lead nuclei. Dielectron production is measured in the fiducial region defined by following requirements: electron transverse momentum pTe > 2.5 GeV, absolute electron pseudorapidity |η e | < 2.5, dielectron invariant mass mee > 5 GeV, and dielectron transverse momentum pTee < 2 GeV. Differential cross-sections are measured as a function of mee, average pTe , absolute dielectron rapidity |yee|, and scattering angle in the dielectron rest frame, |cos θ *|, in the inclusive sample, and also with a requirement of no activity in the forward direction. The total integrated fiducial cross-section is measured to be 215±1(stat.)−20+23(syst.)±4(lumi.) μb. Within experimental uncertainties the measured integrated cross-section is in good agreement with the QED predictions from the Monte Carlo programs Starlight and SuperChic, confirming the broad features of the initial photon fluxes. The differential cross-sections show systematic differences from these predictions which are more pronounced at high |yee | and |cos θ * | values. [Figure not available: see fulltext.]. © 2023, The Author(s).
Citation - WoS: 3
Citation - Scopus: 9
Measurement of Electroweak Z(??¯) ?jj Production and Limits on Anomalous Quartic Gauge Couplings in Pp Collisions at ?s = 13 Tev With the Atlas Detector
(Springer Science and Business Media Deutschland GmbH, 2023) Aad, G.; Abbott, B.; Abbott, D.C.; Abeling, K.; Abidi, S.H.; Aboulhorma, A.; Abramowicz, H.
The electroweak production of Z(??¯) ? in association with two jets is studied in a regime with a photon of high transverse momentum above 150 GeV using proton–proton collisions at a centre-of-mass energy of 13 TeV at the Large Hadron Collider. The analysis uses a data sample with an integrated luminosity of 139 fb?1 collected by the ATLAS detector during the 2015–2018 LHC data-taking period. This process is an important probe of the electroweak symmetry breaking mechanism in the Standard Model and is sensitive to quartic gauge boson couplings via vector-boson scattering. The fiducial Z(??¯) ?jj cross section for electroweak production is measured to be 0.77?0.30+0.34 fb and is consistent with the Standard Model prediction. Evidence of electroweak Z(??¯) ?jj production is found with an observed significance of 3.2? for the background-only hypothesis, compared with an expected significance of 3.7?. The combination of this result with the previously published ATLAS observation of electroweak Z(??¯) ?jj production yields an observed (expected) signal significance of 6.3? (6.6?). Limits on anomalous quartic gauge boson couplings are obtained in the framework of effective field theory with dimension-8 operators. [Figure not available: see fulltext.]. © 2023, The Author(s).
Citation - WoS: 2
Citation - Scopus: 9
Measurement of Exclusive Pion Pair Production in Proton–proton Collisions at √s=7tev With the Atlas Detector
(Institute for Ionics, 2023) Aad, G.; Abbott, B.; Abbott, D.C.; Abeling, K.; Abidi, S.H.; Usman, M.; Uysal, Z.
The exclusive production of pion pairs in the process pp→ ppπ+π- has been measured at s=7TeV with the ATLAS detector at the LHC, using 80μb-1 of low-luminosity data. The pion pairs were detected in the ATLAS central detector while outgoing protons were measured in the forward ATLAS ALFA detector system. This represents the first use of proton tagging to measure an exclusive hadronic final state at the LHC. A cross-section measurement is performed in two kinematic regions defined by the proton momenta, the pion rapidities and transverse momenta, and the pion–pion invariant mass. Cross-section values of 4.8±1.0(stat)-0.2+0.3(syst)μb and 9±6(stat)-2+2(syst)μb are obtained in the two regions; they are compared with theoretical models and provide a demonstration of the feasibility of measurements of this type. © 2023, The Author(s).
Citation - WoS: 39
Citation - Scopus: 45
Measurement of Higgs Boson Decay Into B-Quarks in Associated Production With a Top-Quark Pair in Pp Collisions at Root S=13 Tev With the Atlas Detector
(Springer, 2022) Aad, G.; Abbott, B.; Abbott, D.C.; Abud, A. Abed; Abeling, K.; Abhayasinghe D.K.; The ATLAS Collaboration; Sultansoy, Saleh
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 Hadron Collider between 2015 and 2018 at a centre-of-mass energy of A root s = 13 TeV. The measured signal strength, defined as the ratio of the measured signal yield to that predicted by the Standard Model, is 0.35(-0.34)(+0.36). This result is compatible with the Standard Model prediction and corresponds to an observed (expected) significance of 1.0 (2.7) standard deviations. The signal strength is also measured differentially in bins of the Higgs boson transverse momentum in the simplified template cross-section framework, including a bin for specially selected boosted Higgs bosons with transverse momentum above 300 GeV.