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Title: Search for the associated production of the Higgs boson with a top quark pair in multilepton final states with the ATLAS detector

A search for the associated production of the Higgs boson with a top quark pair is performed in multilepton final states using 20.3 fb–1 of proton–proton collision data recorded by the ATLAS experiment at √s = 8 TeV at the Large Hadron Collider. Five final states, targeting the decays H → WW*, ττ , and ZZ*, are examined for the presence of the Standard Model (SM) Higgs boson: two same-charge light leptons (e or μ) without a hadronically decaying τ lepton; three light leptons; two same-charge light leptons with a hadronically decaying τ lepton; four light leptons; and one light lepton and two hadronically decaying τ leptons. No significant excess of events is observed above the background expectation. The best fit for the tt¯H production cross section, assuming a Higgs boson mass of 125 GeV, is 2.1–1.2+1.4 times the SM expectation, and the observed (expected) upper limit at the 95% confidence level is 4.7 (2.4) times the SM rate. This study shows the p-value for compatibility with the background-only hypothesis is 1.8σ; the expectation in the presence of a Standard Model signal is 0.9σ.
  1. Aix-Marseille Univ. and CNRS/IN2P3, Marseille (France) et al.
Publication Date:
OSTI Identifier:
Grant/Contract Number:
AC02-06CH11357; AC02-05CH11231; SC00112704; AC03-76SF00515
Published Article
Journal Name:
Physics Letters. Section B
Additional Journal Information:
Journal Volume: 749; Journal Issue: C; Journal ID: ISSN 0370-2693
Research Org:
SLAC National Accelerator Lab., Menlo Park, CA (United States); Argonne National Lab. (ANL), Argonne, IL (United States); Brookhaven National Laboratory (BNL), Upton, NY (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
Sponsoring Org:
USDOE Office of Science (SC)
Contributing Orgs:
ATLAS Collaboration
Country of Publication:
United States