Search for direct top squark pair production in events with a Higgs or Z boson, and missing transverse momentum in s = 13 √(s)=13 TeV pp collisions with the ATLAS detector

2017/06/13 by ATLAS Collaboration, M. Aaboud, G. Aad +98 · 2 citations
Physics and Astronomy · #Boson #Electron #Higgs boson #High-Energy Particle Collisions Research #Invariant mass #Large Hadron Collider #Lepton #Nuclear physics #Pair production #Particle Detector Development and Performance #Particle physics #Particle physics theoretical and experimental studies #Physics #Production (economics) #Quark #Standard Model (mathematical formulation) #Supersymmetry #Top quark #hep-ex

paper · pdf · doi:10.1007/jhep08(2017)006

published as JHEP 08 (2017) 006 · 29 pages plus author list + cover pages (46 pages total), 7 figures, 9 tables, submitted to JHEP, All figures including auxiliary figures are available at http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/SUSY-2016-20/

arxiv created 2017/06/13 · openalex publication_date 2017/08/01 · arxiv updated 2017/08/09 · openalex created_date 2020/04/17 · openalex updated_date 2026/08/06

Abstract

A search for direct top squark pair production resulting in events with either a same-flavour opposite-sign dilepton pair with invariant mass compatible with a Z boson or a pair of jets compatible with a Standard Model (SM) Higgs boson (h) is presented. Requirements on additional leptons, jets, jets identified as originating from b-quarks, and missing transverse momentum are imposed to target the other decay products of the top squark pair. The analysis is performed using proton-proton collision data at √(s)=13 TeV collected with the ATLAS detector at the LHC in 2015--2016, corresponding to an integrated luminosity of 36.1 fb^-1. No excess is observed in the data with respect to the SM predictions. The results are interpreted in two sets of models. In the first set, direct production of pairs of lighter top squarks (t₁) with long decay chains involving Z or Higgs bosons is considered. The second set includes direct pair production of the heavier top squark pairs (t₂) decaying via t₂ → Z t₁ or t₂ → h t₁. The results exclude at 95% confidence level t₂ and t₁ masses up to about 800 GeV, extending the exclusion region of supersymmetric parameter space covered by previous LHC searches.

Citations

• Next-to-next-to-leading logarithm resummation fors-channel single top quark production
• Vector Boson Production at Hadron Colliders: A Fully Exclusive QCD Calculation at Next-to-Next-to-Leading Order
• Supergauge transformations in four dimensions
• Event generation with SHERPA 1.1
• Presentation of search results: theCLstechnique
• Is the neutrino a goldstone particle?
• The anti-ktjet clustering algorithm
• NNLO corrections to top pair production at hadron colliders: the quark-gluon reaction

Cited by

• Production of a light top-squark pair in association with a light non-standard Higgs boson within the NMSSM at the 13 TeV LHC and a 33 TeV proton collider
• Broad toplike vector quarks at LHC and HL-LHC