Search for long-lived neutral particles decaying into lepton jets in proton--proton collisions at $\sqrt{s}$ = 8 TeV with the ATLAS detector

Abstract

Several models of physics beyond the Standard Model predict neutral particles that decay into final states consisting of collimated jets of light leptons and hadrons (so-called "lepton jets"). These particles can also be long-lived with decay length comparable to, or even larger than, the LHC detectors' linear dimensions. This paper presents the results of a search for lepton jets in proton--proton collisions at the centre-of-mass energy of $\sqrt{s}$ = 8 TeV in a sample of 20.3 fb${}^{-1}$ collected during 2012 with the ATLAS detector at the LHC. Limits on models predicting Higgs boson decays to neutral long-lived lepton jets are derived as a function of the particle's proper decay length.

arXiv comment30 pages plus author list + cover pages (53 pages total), 17 figures, 11 tables, submitted to JHEP. Replacement of authorlist. All figures including auxiliary figures are available at http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/EXOT-2013-22/

References in corpus (51)

• The anti-k_t jet clustering algorithm
• A Brief Introduction to PYTHIA 8.1
• FastJet user manual
• Asymptotic formulae for likelihood-based tests of new physics
• MadGraph 5 : Going Beyond
• Matching NLO QCD computations and parton shower simulations
• The ATLAS Simulation Infrastructure
• Echoes of a Hidden Valley at Hadron Colliders
• Secluded U(1) below the weak scale
• New Fixed-Target Experiments to Search for Dark Gauge Forces
• Search for a dark photon in e+e- collisions at BABAR
• Improved luminosity determination in pp collisions at sqrt(s) = 7 TeV using the ATLAS detector at the LHC
• Jet energy measurement and its systematic uncertainty in proton-proton collisions at $\sqrt{s}=7$ TeV with the ATLAS detector
• Performance of the ATLAS Trigger System in 2010
• Search for a new gauge boson in the $A^{\prime }$ Experiment (APEX)
• LHC Signals for a SuperUnified Theory of Dark Matter
• Discovering the Higgs Through Highly-Displaced Vertices
• Probing a Secluded U(1) at B-factories
• New Exclusion Limits on Dark Gauge Forces from Proton Bremsstrahlung in Beam-Dump Data
• Phenomenology of Hidden Valleys at Hadron Colliders
• New Exclusion Limits for Dark Gauge Forces from Beam-Dump Data
• Searching for the light dark gauge boson in GeV-scale experiments
• Kinetic Mixing as the Origin of Light Dark Scales
• Discovering New Light States at Neutrino Experiments
• Search for Dimuon Decays of a Light Scalar Boson in Radiative Transitions Upsilon -> gamma A0
• Constraints on sub-GeV hidden sector gauge bosons from a search for heavy neutrino decays
• Limit on the production of a light vector gauge boson in phi meson decays with the KLOE detector
• Search for Light Gauge Bosons of the Dark Sector at the Mainz Microtron
• Dark Sectors and New, Light, Weakly-Coupled Particles
• Search for a vector gauge boson in phi meson decays with the KLOE detector
• Higgs boson decays to four fermions through an abelian hidden sector
• Search for a dark photon in the ${\pi }^0\to e^{+}{e}^{-}\gamma$ decay
• Dark Side of Higgs Diphoton Decays and Muon g-2
• Constraints on Hidden Photon Models from Electron g-2 and Hydrogen Spectroscopy
• Hidden Higgs Decaying to Lepton Jets
• Supernova Constraints on MeV Dark Sectors from e+ e- Annihilations
• Search for pair-produced long-lived neutral particles decaying in the ATLAS hadronic calorimeter in $pp$ collisions at $\sqrt{s}$ = 8 TeV
• Lepton Jets in (Supersymmetric) Electroweak Processes
• Dark Matter Sees The Light
• Search for a non-standard-model Higgs boson decaying to a pair of new light bosons in four-muon final states
• BRIDGE: Branching Ratio Inquiry/Decay Generated Events
• Triggers for displaced decays of long-lived neutral particles in the ATLAS detector
• Constraints on Light Hidden Sector Gauge Bosons from Supernova Cooling
• Discovering Higgs Decays to Lepton Jets at Hadron Colliders
• Search for squarks and gluinos in events with jets and missing transverse energy in ppbar collisions at sqrt(s)=1.96 TeV
• Search for Light Resonances Decaying into Pairs of Muons as a Signal of New Physics
• Search for displaced muonic lepton jets from light Higgs boson decay in proton-proton collisions at sqrt(s) = 7 TeV with the ATLAS detector
• Search for dark photons from supersymmetric hidden valleys
• Search for events with leptonic jets and missing transverse energy in ppbar collisions at sqrt(s)=1.96 TeV
• A search for prompt lepton-jets in pp collisions at sqrt(s) = 7 TeV with the ATLAS detector
• Searching a Dark Photon with HADES

Cited by in corpus (71)

• Illuminating Dark Photons with High-Energy Colliders
• Long-Lived Particles at the Energy Frontier: The MATHUSLA Physics Case
• The Dark Photon
• Searching for long-lived particles beyond the Standard Model at the Large Hadron Collider
• New Detectors to Explore the Lifetime Frontier
• Phenomenology of a 750 GeV Singlet
• Dark Matter Searches at Colliders
• Search for heavy neutral leptons in decays of $W$ bosons produced in 13 TeV $pp$ collisions using prompt and displaced signatures with the ATLAS detector
• Discovering Inelastic Thermal-Relic Dark Matter at Colliders
• Freeze-In Dark Matter with Displaced Signatures at Colliders
• Multilepton and Lepton Jet Probes of Sub-Weak-Scale Right-Handed Neutrinos
• Displaced vertex searches for sterile neutrinos at future lepton colliders
• Search for long-lived particles that decay into final states containing two electrons or two muons in proton-proton collisions at sqrt(s) = 8 TeV
• Powerful Solar Signatures of Long-Lived Dark Mediators
• Search for dark matter at colliders
• A search for pair production of new light bosons decaying into muons
• Sterile neutrino searches via displaced vertices at LHCb
• Displaced vertex signatures of doubly charged scalars in the type-II seesaw and its left-right extensions
• Search for Displaced Supersymmetry in events with an electron and a muon with large impact parameters
• Reinterpretation of LHC Results for New Physics: Status and Recommendations after Run 2
• Searches for dark photons at accelerators
• New Prospects in Fixed Target Searches for Dark Forces with the SeaQuest Experiment at Fermilab
• Cosmological Constraints on Decoupled Dark Photons and Dark Higgs
• Exotic Quarks in Twin Higgs Models
• Search for long-lived neutral particles in $pp$ collisions at $\sqrt{s}$ = 13 TeV that decay into displaced hadronic jets in the ATLAS calorimeter
• A search for pair production of new light bosons decaying into muons in proton-proton collisions at 13 TeV
• A search for prompt lepton-jets in $pp$ collisions at $\sqrt{s}=$ 8 TeV with the ATLAS detector
• Search for long-lived particles in final states with displaced dimuon vertices in $pp$ collisions at $\sqrt{s}=$ 13 TeV with the ATLAS detector
• Compressing the Inert Doublet Model
• Search for new light gauge bosons in Higgs boson decays to four-lepton final states in $pp$ collisions at $\sqrt{s}=8$ TeV with the ATLAS detector at the LHC
• Data-driven Model-independent Searches for Long-lived Particles at the LHC
• Kinetic Mixing and Portal Matter Phenomenology
• Search for long-lived particles with displaced vertices in multijet events in proton-proton collisions at $\sqrt{s}=$ 13 TeV
• Search for light long-lived neutral particles produced in $pp$ collisions at $\sqrt{s}=$ 13 TeV and decaying into collimated leptons or light hadrons with the ATLAS detector
• Search for displaced vertices of oppositely charged leptons from decays of long-lived particles in $pp$ collisions at $\sqrt{s}$ = 13 TeV with the ATLAS detector
• The NMSSM lives: with the 750 GeV diphoton excess
• Displaced vertex signature of type-I seesaw
• Lepton-Jets and Low-Mass Sterile Neutrinos at Hadron Colliders
• Search for the Higgs boson produced in association with a $W$ boson and decaying to four $b$-quarks via two spin-zero particles in $pp$ collisions at 13 TeV with the ATLAS detector
• Supersymmetric sphaleron configurations as the origin of the perplexing ANITA events
• Simplified Models for Displaced Dark Matter Signatures
• Towards A UV-Model of Kinetic Mixing and Portal Matter
• Dark Matter Annihilation Decay at The LHC
• Displaced Vertices from Pseudo-Dirac Dark Matter
• Searching for a light $Z^{\prime }$ through Higgs production at the LHC
• Searching for Dark Photons at the LHeC and FCC-he
• Displaced Vertices from X-ray Lines
• Faking SM Photons by Displaced Dark Photon Decays
• Rare $Z$ Boson Decays to a Hidden Sector
• Search for the production of a long-lived neutral particle decaying within the ATLAS hadronic calorimeter in association with a $Z$ boson from $pp$ collisions at $\sqrt{s}=13$ TeV
• CP-violating Dark Photon Interaction
• Challenges for a QCD Axion at the 10 MeV Scale
• A Framework for Finding Anomalous Objects at the LHC
• Detecting multimuon jets from the Higgs exotic decays in the Higgs portal framework
• Novel signatures for long-lived particles at the LHC
• Examining the origin of dark matter mass at colliders
• Leptophilic Composite Asymmetric Dark Matter and its Detection
• Searching for Metastable Particles with Sub-Millimeter Displaced Vertices at Hadron Colliders
• Right-handed neutrinos: the hunt is on!
• Boosted scalar confronting 750 GeV di-photon excess
• Quantum Simulations of Dark Sector Showers
• Supersymmetric Higgs-portal and X-ray lines
• TeV-scale Pseudo-Dirac Seesaw Mechanisms in an E${}_6$ Inspired Model
• Angular distribution as an effective probe of new physics in semi-hadronic three-body meson decays
• Searches for Light Scalars, Pseudoscalars, and Gauge Bosons
• Beyond Standard Model Higgs
• Constraining portals with displaced Higgs decay searches at the LHC
• Massively Parallel Computing at the Large Hadron Collider up to the HL-LHC
• Searches for Exotic Phenomena at ATLAS and CMS
• Muon Beam Dump Experiments probe five-dimensional nature of $U(1{)}_{L_{\mu }-L_{\tau }}$
• Search for non Standard Model Higgs boson decays in events with displaced muon-jets