Search for the associated production of the Higgs boson with a top quark pair in multilepton final states with the ATLAS detector
Number of Authors: 2828
2015 (English)In: Physics Letters B, ISSN 0370-2693, E-ISSN 1873-2445, Vol. 749, 519-541 p.Article in journal (Refereed) Published
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 root s = 8 TeVat the Large Hadron Collider. Five final states, targeting the decays H -> WW*, tau tau, and ZZ*, are examined for the presence of the Standard Model (SM) Higgs boson: two same-charge light leptons (e or mu) without a hadronically decaying tau lepton; three light leptons; two same-charge light leptons with a hadronically decaying tau lepton; four light leptons; and one light lepton and two hadronically decaying tau leptons. No significant excess of events is observed above the background expectation. The best fit for the t (t) over barH 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. The p-value for compatibility with the background-only hypothesis is 1.8s; the expectation in the presence of a Standard Model signal is 0.9 sigma.
Place, publisher, year, edition, pages
2015. Vol. 749, 519-541 p.
IdentifiersURN: urn:nbn:se:su:diva-125026DOI: 10.1016/j.physletb.2015.07.079ISI: 000361562900076OAI: oai:DiVA.org:su-125026DiVA: diva2:891542