Search for pair-produced third-generation squarks decaying via charm quarks or in compressed supersymmetric scenarios in $pp$ collisions at $\sqrt{s}=8$TeV with the ATLAS detector

Abstract

Results of a search for supersymmetry via direct production of third-generation squarks are reported, using $20.3$ fb${}^{-1}$ of proton-proton collision data at $\sqrt{s}=8$ TeV recorded by the ATLAS experiment at the LHC in 2012. Two different analysis strategies based on monojet-like and $c$-tagged event selections are carried out to optimize the sensitivity for direct top squark pair production in the decay channel to a charm quark and the lightest neutralino (${\tilde{t}}_1\to c+{\tilde{\chi }}_1^0$) across the top squark--neutralino mass parameter space. No excess above the Standard Model background expectation is observed. The results are interpreted in the context of direct pair production of top squarks and presented in terms of exclusion limits in the ($m_{{\tilde{t}}_1}$, $m_{{\tilde{\chi }}_1^0}$) parameter space. A top squark of mass up to about 240 GeV is excluded at 95$\%$ confidence level for arbitrary neutralino masses, within the kinematic boundaries. Top squark masses up to 270 GeV are excluded for a neutralino mass of 200 GeV. In a scenario where the top squark and the lightest neutralino are nearly degenerate in mass, top squark masses up to 260 GeV are excluded. The results from the monojet-like analysis are also interpreted in terms of compressed scenarios for top squark pair production in the decay channel ${\tilde{t}}_1\to b+f{f}^{{}^{\prime }}+{\tilde{\chi }}_1^0$ and sbottom pair production with ${\tilde{b}}_1\to b+{\tilde{\chi }}_1^0$, leading to a similar exclusion for nearly mass-degenerate third-generation squarks and the lightest neutralino. The results in this paper significantly extend previous results at colliders.

24 pages + author list + 1 cover page (35 pages in total), 11 figures, 9 tables, submitted to Physical Review D, All figures including auxiliary figures are available at http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/SUSY-2013-21/

References in corpus (13)

• PYTHIA 6.4 Physics and Manual
• Parton distributions for the LHC
• New parton distributions for collider physics
• Event generation with SHERPA 1.1
• An NNLO subtraction formalism in hadron collisions and its application to Higgs boson production at the LHC
• Vector boson pair production at the LHC
• Vector boson production at hadron colliders: a fully exclusive QCD calculation at NNLO
• Two-loop soft anomalous dimensions for single top quark associated production with a W- or H-
• Electron reconstruction and identification efficiency measurements with the ATLAS detector using the 2011 LHC proton-proton collision data
• Search for direct top-squark pair production in final states with two leptons in pp collisions at sqrt(s)=8TeV with the ATLAS detector
• Electroweak corrections to W + jet hadroproduction including leptonic W-boson decays
• Search for direct top squark pair production in final states with one isolated lepton, jets, and missing transverse momentum in sqrt(s) = 7 TeV pp collisions using 4.7 fb-1 of ATLAS data
• Search for scalar top quarks in the acoplanar charm jets and missing transverse energy final state in $p\bar{p}$ collisions at $\sqrt{s}=1.96$ TeV

Cited by in corpus (29)

• The Dawn of FIMP Dark Matter: A Review of Models and Constraints
• WIMPs at the Galactic Center
• Search for squarks and gluinos in events with isolated leptons, jets and missing transverse momentum at $\sqrt{s}=8$ TeV with the ATLAS detector
• Signatures of Majorana dark matter with t-channel mediators
• Discovery Prospects for NMSSM Higgs Bosons at the High-Energy Large Hadron Collider
• Anatomy of Coannihilation with a Scalar Top Partner
• Search for direct production of supersymmetric partners of the top quark in the all-jets final state in proton-proton collisions at sqrt(s) = 13 TeV
• Accessing the core of naturalness, nearly degenerate higgsinos, at the LHC
• Dirac dark matter with a charged mediator: a comprehensive one-loop analysis of the direct detection phenomenology
• Search for Scalar Charm Quark Pair Production in pp Collisions at $\sqrt{s}=8$ TeV with the ATLAS Detector
• Search for supersymmetry in events with large missing transverse momentum, jets, and at least one tau lepton in 20 fb${}^{-1}$ of $\sqrt{s}$=8 TeV proton-proton collision data with the ATLAS detector
• NMSSM explanations of the Galactic center gamma ray excess and promising LHC searches
• Non-universal Gaugino mass models under the lamppost of muon (g-2)
• Catching sparks from well-forged neutralinos
• Experimental Status of Supersymmetry after the LHC Run-I
• Spot the stop with a b-tag
• Monojet searches for momentum-dependent dark matter interactions
• Sneutrino DM in the NMSSM with inverse seesaw mechanism
• 1-loop SQCD corrections to the decay of top-squarks to charm and neutralino in the generic MSSM
• Implications of a Electroweak Triplet Scalar Leptoquark on the Ultra-High Energy Neutrino Events at IceCube
• Second Stop and Sbottom Searches with a Stealth Stop
• Auto-Concealment of Supersymmetry in Extra Dimensions
• Investigating the Quantum Properties of Jets and the Search for a Supersymmetric Top Quark Partner with the ATLAS Detector
• Baryogenesis: A small review of the big picture
• The Status of Supersymmetry after the LHC Run 1
• Implications of the Fermi-LAT Pass 8 Galactic Center Excess on Supersymmetric Dark Matter
• Light stop squarks and b-tagging
• Aspects of astrophysical particle production and beyond the Standard Model phenomenology
• Higher-order QCD corrections to supersymmetric particle production and decay at the LHC