Exploring the nearly degenerate stop region with sbottom decays

Abstract

A light stop with mass almost degenerate with the lightest neutralino has important connections with both naturalness and dark matter relic abundance. This region is also very hard to probe at colliders. In this paper, we demonstrate the potential of searching for such stop particles at the LHC from sbottom decays, focusing on two channels with final states $2\ell +E_{\mathrm{T}}^{\mathrm{miss}}$ and $1b1\ell +E_{\mathrm{T}}^{\mathrm{miss}}$. We found that, if the lightest sbottom has mass around or below 1 TeV and has a significant branching ratio to decay to stop and $W$ ($\tilde{b}\to \tilde{t}W$), a stop almost degenerate with neutralino can be excluded up to about 500-600 GeV at the 13 TeV LHC with $300{\mathrm{fb}}^{-1}$ data. The searches we propose are complementary to other SUSY searches at the LHC and could have the best sensitivity to the stop-bino coannihilation region. Since they involve final states which have already been used in LHC searches, a reinterpretation of the search results already has sensitivity. Further optimization could deliver the full potential of these channels.

26 pages, 6 figures, v2: minor corrections, references added, matches published version in JHEP

References in corpus (25)

• PYTHIA 6.4 Physics and Manual
• The automated computation of tree-level and next-to-leading order differential cross sections, and their matching to parton shower simulations
• Vector boson pair production at the LHC
• micrOMEGAs4.1: two dark matter candidates
• Squark and gluino production cross sections in pp collisions at $\sqrt{s}$ = 13, 14, 33 and 100 TeV
• Searches for electroweak production of charginos, neutralinos, and sleptons decaying to leptons and W, Z, and Higgs bosons in pp collisions at 8 TeV
• Neutralino Dark Matter at 14 and 100 TeV
• Search for new phenomena in final states with an energetic jet and large missing transverse momentum in $pp$ collisions at $\sqrt{s}=13$ TeV using the ATLAS detector
• 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
• Stop the Top Background of the Stop Search
• Measurement of Spin Correlation in Top-Antitop Quark Events and Search for Top Squark Pair Production in pp Collisions at $\sqrt{s}=8$ TeV Using the ATLAS Detector
• Search for top-squark pairs decaying into Higgs or Z bosons in pp collisions at sqrt(s) = 8 TeV
• Search for top squarks in final states with one isolated lepton, jets, and missing transverse momentum in $\sqrt{s}=13$ TeV $pp$ collisions with the ATLAS detector
• Measurement of the top quark pair production cross section in the lepton+jets channel in proton-antiproton collisions at $\sqrt{s}$=1.96 TeV
• Light Stop Searches at the LHC in Events with One Hard Photon or Jet and Missing Energy
• Closing the stop gap
• Measurements of spin correlation in top-antitop quark events from proton-proton collisions at $\sqrt{s}=7$ TeV using the ATLAS detector
• Measurement of ttbar Spin Correlation in ppbar Collisions Using the CDF II Detector at the Tevatron
• Measurement of spin correlation in ttbar production using dilepton final states
• Search for bottom squark pair production in proton--proton collisions at $\sqrt{s}=$13 TeV with the ATLAS detector
• New limits on top squark NLSP from ATLAS 4.7 $f{b}^{-1}$ data
• Search for top squark pair production in compressed-mass-spectrum scenarios in proton-proton collisions at sqrt(s) = 8 TeV using the alpha[T] variable
• Spot the stop with a b-tag
• Stop Search in the Compressed Region via Semileptonic Decays
• Second Stop and Sbottom Searches with a Stealth Stop

Cited by in corpus (3)

• Stop Co-Annihilation in the Minimal Supersymmetric Standard Model Revisited
• Enhancing the discovery prospects for SUSY-like decays with a forgotten kinematic variable
• On the ATLAS Top Mass Measurements and the Potential for Stealth Stop Contamination