Search for long-lived, massive particles in events with displaced vertices and multiple jets in $pp$ collisions at $\sqrt{s}=13$ TeV with the ATLAS detector

Abstract

A search for long-lived particles decaying into hadrons is presented. The analysis uses 139 fb${}^{-1}$ of $pp$ collision data collected at $\sqrt{s}=13$ TeV by the ATLAS detector at the LHC using events that contain multiple energetic jets and a displaced vertex. The search employs dedicated reconstruction techniques that significantly increase the sensitivity to long-lived particles decaying in the ATLAS inner detector. Background estimates for Standard Model processes and instrumental effects are extracted from data. The observed event yields are compatible with those expected from background processes. The results are used to set limits at 95% confidence level on model-independent cross sections for processes beyond the Standard Model, and on scenarios with pair-production of supersymmetric particles with long-lived electroweakinos that decay via a small $R$-parity-violating coupling. The pair-production of electroweakinos with masses below 1.5 TeV is excluded for mean proper lifetimes in the range from 0.03 ns to 1 ns. When produced in the decay of $m(\tilde{g})=2.4$ TeV gluinos, electroweakinos with $m({\tilde{\chi }}_1^0)=1.5$ TeV are excluded with lifetimes in the range of 0.02 ns to 4 ns.

arXiv commentComments: 28 pages in total, author list starting page 29, 13 figures, 6 tables, published in JHEP. All figures including auxiliary figures are available at http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/SUSY-2018-13

References in corpus (28)

• 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 for the LHC
• Asymptotic formulae for likelihood-based tests of new physics
• Parton distributions with LHC data
• PDF4LHC recommendations for LHC Run II
• R-parity violating supersymmetry
• Supersymmetric Unification Without Low Energy Supersymmetry And Signatures for Fine-Tuning at the LHC
• Echoes of a Hidden Valley at Hadron Colliders
• The Production of Charginos/Neutralinos and Sleptons at Hadron Colliders
• Threshold resummation for squark-antisquark and gluino-pair production at the LHC
• Soft gluon resummation for the production of gluino-gluino and squark-antisquark pairs at the LHC
• Soft-gluon resummation for squark and gluino hadroproduction
• Squark and gluino production cross sections in pp collisions at $\sqrt{s}$ = 13, 14, 33 and 100 TeV
• Correcting the Colour-Dipole Cascade Model with Fixed Order Matrix Elements
• Precision predictions for electroweak superpartner production at hadron colliders with Resummino
• Matching Tree-Level Matrix Elements with Interleaved Showers
• Gaugino production in proton-proton collisions at a center-of-mass energy of 8 TeV
• Bounds on $\Delta B=1$ Couplings in the Supersymmetric Standard Model
• NNLL-fast: predictions for coloured supersymmetric particle production at the LHC with threshold and Coulomb resummation
• Collider Searches for Long-Lived Particles Beyond the Standard Model
• Threshold resummation for gaugino pair production at hadron colliders
• NNLL resummation for squark and gluino production at the LHC
• NNLL resummation for squark-antisquark pair production at the LHC
• Towards NNLL resummation: hard matching coefficients for squark and gluino hadroproduction
• Slepton pair production at the LHC in NLO+NLL with resummation-improved parton densities

Cited by in corpus (11)

• Energetic long-lived particles in the CMS muon chambers
• Status of R-parity violating SUSY
• Search for long-lived particles using displaced vertices and missing transverse momentum in proton-proton collisions at $\sqrt{s}$ = 13 TeV
• Long live The NMSSM!
• Probing conversion-driven freeze-out at the LHC
• Search for emerging jets in $pp$ collisions at $\sqrt{s}=13.6$ TeV with the ATLAS experiment
• Search for light long-lived particles in $pp$ collisions at $\sqrt{s}=13$ TeV using displaced vertices in the ATLAS inner detector
• t-channel dark matter at the LHC -- a whitepaper
• Visible Collider Signals of Natural Quirks
• Search for new physics in jet multiplicity patterns of multilepton events at $\sqrt{s}$ = 13 TeV
• Search for long-lived particles using displaced vertices of oppositely charged leptons in 140 fb${}^{-1}$ of pp collisions at $\sqrt{s}=13$ TeV with the ATLAS detector