Search for long-lived neutral particles produced in $pp$ collisions at $\sqrt{s}=13$ TeV decaying into displaced hadronic jets in the ATLAS inner detector and muon spectrometer

Abstract

A search is presented for pair-production of long-lived neutral particles using 33 fb${}^{-1}$ of $\sqrt{s}=13$ TeV proton-proton collision data, collected during 2016 by the ATLAS detector at the LHC. This search focuses on a topology in which one long-lived particle decays in the ATLAS inner detector and the other decays in the muon spectrometer. Special techniques are employed to reconstruct the displaced tracks and vertices in the inner detector and in the muon spectrometer. One event is observed that passes the full event selection, which is consistent with the estimated background. Limits are placed on scalar boson propagators with masses from 125 GeV to 1000 GeV decaying into pairs of long-lived hidden-sector scalars with masses from 8 GeV to 400 GeV. The limits placed on several low-mass scalars extend previous exclusion limits in the range of proper lifetimes $c\tau$ from 5 cm to 1 m.

43 pages in total, author list starting page 27, 6 figures, 9 tables. All figures including auxiliary figures are available at http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/EXOT-2018-61

References in corpus (17)

• The automated computation of tree-level and next-to-leading order differential cross sections, and their matching to parton shower simulations
• An Introduction to PYTHIA 8.2
• Parton distributions for the LHC
• Echoes of a Hidden Valley at Hadron Colliders
• Combined measurements of Higgs boson production and decay using up to $80$ fb${}^{-1}$ of proton-proton collision data at $\sqrt{s}=$ 13 TeV collected with the ATLAS experiment
• Study of the material of the ATLAS inner detector for Run 2 of the LHC
• Big Bang Nucleosynthesis Constraints on Hadronically and Electromagnetically Decaying Relic Neutral Particles
• Discovering the Higgs Through Highly-Displaced Vertices
• Phenomenology of Hidden Valleys at Hadron Colliders
• Search for long-lived neutral particles decaying to quark-antiquark pairs in proton-proton collisions at sqrt(s) = 8 TeV
• Possible Effects of a Hidden Valley on Supersymmetric Phenomenology
• Search for pair-produced long-lived neutral particles decaying in the ATLAS hadronic calorimeter in $pp$ collisions at $\sqrt{s}$ = 8 TeV
• Search for a light Higgs boson decaying to long-lived weakly-interacting particles in proton-proton collisions at sqrt(s) = 7 TeV with the ATLAS detector
• Search for long-lived neutral particles in $pp$ collisions at $\sqrt{s}$ = 13 TeV that decay into displaced hadronic jets in the ATLAS calorimeter
• Search for long-lived particles decaying to jet pairs
• Performance of the reconstruction of large impact parameter tracks in the inner detector of ATLAS
• A measurement of material in the ATLAS tracker using secondary hadronic interactions in 7 TeV pp collisions

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• Search for long-lived particles decaying to leptons with large impact parameter in proton-proton collisions at $\sqrt{s}$ = 13 TeV
• Searching for Elusive Dark Sectors with Terrestrial and Celestial Observations
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• Searching for Flavor-Violating ALPs in Higgs Decays
• Long-Lived Light Mediators from Higgs boson Decay at HL-LHC, FCC-hh and a Proposal of Dedicated LLP Detectors for FCC-hh
• Determining the lifetime of long-lived particles at the HL-LHC
• Long-lived Particles Anomaly Detection with Parametrized Quantum Circuits
• Search for light long-lived particles in $pp$ collisions at $\sqrt{s}=13$ TeV using displaced vertices in the ATLAS inner detector
• Exotic Higgs decays into displaced jets at the LHeC
• Sub-GeV dark matter and multi-decay signatures from dark showers at beam-dump experiments
• Long-lived Light Mediators in a Higgs Portal Model at the FCC-ee
• Proposal for a shared transverse LLP detector for FCC-ee and FCC-hh and a forward LLP detector for FCC-hh
• Displaced fat-jets and tracks to probe boosted right-handed neutrinos in the $U(1{)}_{B-L}$ model