Search for displaced leptons in $\sqrt{s}=13$ TeV and $13.6$ TeV $pp$ collisions with the ATLAS detector

Abstract

A search for leptons displaced from the primary vertex is performed with the ATLAS detector at the Large Hadron Collider. The search includes the full proton-proton collision dataset collected during Run 2 at $\sqrt{s}=13$ TeV and a partial dataset collected during Run 3 in 2022-2023 at $\sqrt{s}=13.6$ TeV, corresponding to integrated luminosities of 140 fb${}^{-1}$ and 56.3 fb${}^{-1}$, respectively. Final states with displaced electrons or muons are considered, and novel triggers introduced in Run 3 are employed that use large impact parameter tracking to reconstruct displaced tracks with low momentum. In addition, photon reconstruction and multivariate techniques are employed to broaden the sensitivity to channels with large background rates or highly displaced electrons, respectively. The results are consistent with the Standard Model background expectations and are used to set model-independent limits on the production of displaced electrons and muons. The analysis is also interpreted in the context of a gauge-mediated supersymmetry breaking model with pair-produced long-lived sleptons, and a dark sector model with pair-produced chargino-like states. The results include 95% CL exclusions of selectrons with lifetimes from 4 ps to 60 ns and a mass of 150 GeV, and exclusions of selectrons, smuons, and staus with a lifetime of 0.3 ns for masses up to 740 GeV, 830 GeV, and 440 GeV, respectively. Dark charginos with masses up to 380 GeV are excluded for a mass difference with the neutral state of 40 GeV, and mass differences down to 17 GeV are excluded for dark charginos with a 100 GeV mass.

arXiv comment49 pages in total, author list starting page 32, 9 figures, 3 tables. All figures including auxiliary figures are available at http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/SUSY-2022-11

References in corpus (54)

• The automated computation of tree-level and next-to-leading order differential cross sections, and their matching to parton shower simulations
• The anti-k_t jet clustering algorithm
• An Introduction to PYTHIA 8.2
• FastJet user manual
• Parton distributions with LHC data
• EPOS LHC : test of collective hadronization with LHC data
• Bounds on Universal Extra Dimensions
• R-parity violating supersymmetry
• Supersymmetric Unification Without Low Energy Supersymmetry And Signatures for Fine-Tuning at the LHC
• Performance of the ATLAS Trigger System in 2015
• Electron and photon performance measurements with the ATLAS detector using the 2015-2017 LHC proton-proton collision data
• Simplified Models for LHC New Physics Searches
• The Production of Charginos/Neutralinos and Sleptons at Hadron Colliders
• Simplified Models for a First Characterization of New Physics at the LHC
• Jet reconstruction and performance using particle flow with the ATLAS Detector
• Performance of electron and photon triggers in ATLAS during LHC Run 2
• Muon reconstruction and identification efficiency in ATLAS using the full Run 2 $pp$ collision data set at $\sqrt{s}=13$ TeV
• Bosonic Supersymmetry? Getting Fooled at the LHC
• ATLAS data quality operations and performance for 2015-2018 data-taking
• Performance of the ATLAS muon triggers in Run 2
• Searches for supersymmetric particles in e+e- collisions up to 208 GeV and interpretation of the results within the MSSM
• Precision predictions for electroweak superpartner production at hadron colliders with Resummino
• Split Supersymmetry
• Gaugino production in proton-proton collisions at a center-of-mass energy of 8 TeV
• Luminosity determination in $pp$ collisions at $\sqrt{s}=13$ TeV using the ATLAS detector at the LHC
• Searching for Directly Decaying Gluinos at the Tevatron
• Threshold resummation for gaugino pair production at hadron colliders
• Revisiting slepton pair production at the Large Hadron Collider
• Threshold Resummation for Slepton-Pair Production at Hadron Colliders
• Slepton pair production at the LHC in NLO+NLL with resummation-improved parton densities
• Search for gauge mediated SUSY breaking topologies in e+e- collisions at centre-of-mass energies up to 209GeV
• Long-Lived Staus and Displaced Leptons at the LHC
• Search for long-lived charginos based on a disappearing-track signature using 136 fb${}^{-1}$ of $pp$ collisions at $\sqrt{s}$ = 13 TeV with the ATLAS detector
• Software and computing for Run 3 of the ATLAS experiment at the LHC
• Neutralino/chargino pair production at NLO+NLL with resummation-improved PDFs for LHC Run II
• Mass Spectrum in R-Parity Violating mSUGRA and Benchmark Points
• The ATLAS Inner Detector Trigger performance in pp collisions at 13 TeV during LHC Run 2
• Search for long-lived, massive particles in events with a displaced vertex and a muon with large impact parameter in $pp$ collisions at $\sqrt{s}=13$ TeV with the ATLAS detector
• Search for displaced leptons in $\sqrt{s}=13$ TeV $pp$ collisions with the ATLAS detector
• The ATLAS Experiment at the CERN Large Hadron Collider: A Description of the Detector Configuration for Run 3
• Searches for Gauge-Mediated Supersymmetry Breaking Topologies in e+e- collisions at LEP2
• Performance of the reconstruction of large impact parameter tracks in the inner detector of ATLAS
• Search for supersymmetric particles in light gravitino scenarios and sleptons NLSP
• The ATLAS Trigger System for LHC Run 3 and Trigger performance in 2022
• Long live the Higgs portal!
• Emulating the impact of additional proton-proton interactions in the ATLAS simulation by pre-sampling sets of inelastic Monte Carlo events
• Search for heavy, long-lived, charged particles with large ionisation energy loss in $pp$ collisions at $\sqrt{s}=13\text{TeV}$ using the ATLAS experiment and the full Run 2 dataset
• Search for long-lived particles decaying to leptons with large impact parameter in proton-proton collisions at $\sqrt{s}$ = 13 TeV
• Electroweak superpartner production at 13.6 TeV with Resummino
• Software Performance of the ATLAS Track Reconstruction for LHC Run 3
• Search for supersymmetry in final states with disappearing tracks in proton-proton collisions at $\sqrt{s}$ = 13 TeV
• Soft displaced leptons at the LHC
• Search for displaced photons produced in exotic decays of the Higgs boson using 13 TeV $pp$ collisions with the ATLAS detector
• Search for pairs of muons with small displacements in $pp$ collisions at $\sqrt{s}=13$ TeV with the ATLAS detector