1,742,461 research outputs found
ATLAS Collaboration Maps
No full textMaps showing the institution countries of the ATLAS Collaboration and the nationalities of ATLAS members. For PDF versions of these maps, please refer to links below. (Collaboration Map updated November 2024, Nationalities Map updated June 2022
Higgs boson production cross-section measurements vand their EFT interpretation in the 4l decay channel at root s =13 TeV with the ATLAS detector (vol 80, 10.1140/epjc/s10052-020-8227-9, 2020)
No full textIn the published HTML version of this article, the affiliations of the authors of the National Research Nuclear University MEPhI, Moscow, Russia were unfortunately marked incorrectly. © 2021, CERN for the benefit of the ATLAS collaboration
Search for squarks and gluinos in final states with one ivsolated lepton, jets, and missing transverse momentum at root s = 13 TeV with the ATLAS detector (vol 81, 600, 2021)
No full textIn this article the title was incorrectly given as ‘Search for squarks and gluinos in final states with one isolated lepton, jets, and missing transverse momentum at √s = 13 with the ATLAS detector’ but should have been ‘Search for squarks and gluinos in final states with one isolated lepton, jets, and missing transverse momentum at √s = 13 TeV with the ATLAS detector’. The original article has been corrected. © 2021, CERN for the benefit of ATLAS Collaboration
Search for the charged-lepton-flavor-violating decay Z →eμ in pp collisions at √s =13 TeV with the ATLAS detector
No full textA search for the charged-lepton-flavor-violating process Formula Presented is presented, using Formula Presented of Formula Presented Formula Presented collision data collected by the ATLAS experiment at the LHC. An excess in the Formula Presented invariant mass spectrum near the Formula Presented boson mass would be a striking signature of new physics. No excess is observed, and an upper limit Formula Presented is placed on the branching fraction at 95% confidence level, which is the most stringent limit to date. © 2023 CERN, for the ATLAS Collaboration
Search for a new gauge boson via the process in collisions at with the ATLAS detector
No full textA search for a new Z′ gauge boson predicted by Lμ-Lτ models, based on charged-current Drell-Yan production, pp→W±(∗)→Z′μ±ν→μ±μ μ±ν, is presented. The data sample used corresponds to an integrated luminosity of 140 fb-1 of proton-proton collisions at s=13 TeV recorded by the ATLAS detector at the Large Hadron Collider. The search examines a final state of 3μ plus large missing transverse momentum. Upper limits are set on the Z′ production cross section times branching ratio in the mass range of 5-81 GeV. After combining with the previous Z′ search using the neutral-current Drell-Yan production with a 4μ final state, the most stringent exclusion limits to date are achieved in the parameter space of the Z′ coupling strength and mass. © 2024 CERN, for the ATLAS Collaboration. Published by the American Physical Society under the terms of the 'https://creativecommons.org/licenses/by/4.0/'Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI. Funded by SCOAP3
Performance of the reconstruction of large impact parameter tracks in the inner detector of ATLAS
Full text linkSearches for long-lived particles (LLPs) are among the most promising avenues for discovering physics beyond the Standard Model at the Large Hadron Collider (LHC). However, displaced signatures are notoriously difficult to identify due to their ability to evade standard object reconstruction strategies. In particular, the ATLAS track reconstruction applies strict pointing requirements which limit sensitivity to charged particles originating far from the primary interaction point. To recover efficiency for LLPs decaying within the tracking detector volume, the ATLAS Collaboration employs a dedicated large-radius tracking (LRT) pass with loosened pointing requirements. During Run 2 of the LHC, the LRT implementation produced many incorrectly reconstructed tracks and was therefore only deployed in small subsets of events. In preparation for LHC Run 3, ATLAS has significantly improved both standard and large-radius track reconstruction performance, allowing for LRT to run in all events. This development greatly expands the potential phase-space of LLP searches and streamlines LLP analysis workflows. This paper will highlight the above achievement and report on the readiness of the ATLAS detector for track-based LLP searches in Run 3. © 2023, The Author(s)
ATLAS flavour-tagging algorithms for the LHC Run 2 pp collision dataset
Full text linkThe flavour-tagging algorithms developed by the ATLAS Collaboration and used to analyse its dataset of s=13 TeV pp collisions from Run 2 of the Large Hadron Collider are presented. These new tagging algorithms are based on recurrent and deep neural networks, and their performance is evaluated in simulated collision events. These developments yield considerable improvements over previous jet-flavour identification strategies. At the 77% b-jet identification efficiency operating point, light-jet (charm-jet) rejection factors of 170 (5) are achieved in a sample of simulated Standard Model tt ̄ events; similarly, at a c-jet identification efficiency of 30%, a light-jet (b-jet) rejection factor of 70 (9) is obtained
Measurement of single top-quark production in association with a boson in collisions at with the ATLAS detector
No full textThe inclusive cross section for the production of a single top quark in association with a Formula Presented boson is measured using Formula Presented of proton-proton collision data collected with the ATLAS detector at Formula Presented. Events containing two charged leptons and at least one jet identified as originating from a Formula Presented-quark are selected. A multivariate discriminant is constructed to separate the Formula Presented signal from the Formula Presented background. The cross section is extracted using a profile likelihood fit to the signal and control regions and it is measured to be Formula Presented, in good agreement with the Standard Model prediction. The measured cross section is used to extract a value for the left-handed form factor at the Formula Presented vertex times the Cabibbo-Kobayashi-Maskawa matrix element Formula Presented of Formula Presented. © 2024 CERN, for the ATLAS Collaboration
Search for Heavy Neutral Leptons in Decays of W Bosons Using a Dilepton Displaced Vertex in s=13 TeV pp Collisions with the ATLAS Detector
No full textA search for a long-lived, heavy neutral lepton ( N ) in 139 fb - 1 of s = 13 TeV p p collision data collected by the ATLAS detector at the Large Hadron Collider is reported. The N is produced via W → N μ or W → N e and decays into two charged leptons and a neutrino, forming a displaced vertex. The N mass is used to discriminate between signal and background. No signal is observed, and limits are set on the squared mixing parameters of the N with the left-handed neutrino states for the N mass range 3 GeV < m N < 15 GeV . For the first time, limits are given for both single-flavor and multiflavor mixing scenarios motivated by neutrino flavor oscillation results for both the normal and inverted neutrino-mass hierarchies. © 2023 CERN, for the ATLAS Collaboration
First t-channel single top measurement in pp collisions at an energy in the centre-of-mass of √s = 5.02 TeV with the ATLAS experiment
Full text linkA single top quark production measurement in proton-proton (pp) collisions at the Large Hadron Collider (LHC) at an energy in the centre-of-mass √s = 5.02 TeV with data collected by the ATLAS experiment is reported. This analysis uses a Boosted Decision Tree (BDT) to separate signal from background events and its output distribution is used for a Profile-Likelihood fit. Some of the calibrations used in this analysis are taken from a recent ATLAS top quark pair production cross-section measurement at the same energy of √s = 5.02 TeV (ATLAS Collaboration, JHEP, 06 (2023) 138). The analysis takes into account forward jets to enhance the t-channel process, with an ad-hoc calibration for their energy
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