Search for pair production of heavy vector-like quarks decaying to high-p(T) W bosons and b quarks in the lepton-plus-jets final state in pp collisions at root s=13 TeV with the ATLAS detector


Aaboud M., Aad G., Abbott B., Abdinov O., Abeloos B., Abidi S. H., ...More

JOURNAL OF HIGH ENERGY PHYSICS, no.10, 2017 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Publication Date: 2017
  • Doi Number: 10.1007/jhep10(2017)141
  • Journal Name: JOURNAL OF HIGH ENERGY PHYSICS
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Keywords: Exotics, Hadron-Hadron scattering (experiments), HADRON COLLIDERS, CROSS-SECTION, DISTRIBUTIONS
  • Gazi University Affiliated: Yes

Abstract

A search is presented for the pair production of heavy vector-like T quarks, primarily targeting the T quark decays to a W boson and a b-quark. The search is based on 36: 1 fb(-1) of pp collisions at root s = 13TeV recorded in 2015 and 2016 with the ATLAS detector at the CERN Large Hadron Collider. Data are analysed in the lepton-plus-jets final state, including at least one b-tagged jet and a large-radius jet identified as originating from the hadronic decay of a high-momentum W boson. No significant deviation from the Standard Model expectation is observed in the reconstructed T mass distribution. The observed 95% confidence level lower limit on the T mass are 1350 GeV assuming 100% branching ratio to Wb. In the SU(2) singlet scenario, the lower mass limit is 1170 GeV. This search is also sensitive to a heavy vector-like B quark decaying to Wt and other final states. The results are thus reinterpreted to provide a 95% con fidence level lower limit on the B quark mass at 1250 GeV assuming 100% branching ratio to Wt; in the SU(2) singlet scenario, the limit is 1080 GeV. Mass limits on both T and B production are also set as a function of the decay branching ratios. The 100% branching ratio limits are found to be applicable to heavy vector-like Y and X production that decay to Wb and Wt, respectively.