Search for H -> gamma gamma produced in association with top quarks and constraints on the Yukawa coupling between the top quark and the Higgs boson using data taken at 7 TeV and 8 TeV with the ATLAS detector
Number of Authors: 2896
2015 (English)In: Physics Letters B, ISSN 0370-2693, Vol. 740, 222-242 p.Article in journal (Refereed) Published
This Letter presents a search at the LHC for s-channel single top-quark production in proton-proton collisions at a centre-of-mass energy of 8 TeV. The analyzed data set was recorded by the ATLAS detector and corresponds to an integrated luminosity of 20.3 fb(-1). Selected events contain one charged lepton, large missing transverse momentum and exactly two b-tagged jets. A multivariate event classifier based on boosted decision trees is developed to discriminate s-channel single top-quark events from the main background contributions. The signal extraction is based on a binned maximum-likelihood fit of the output classifier distribution. The analysis leads to an upper limit on the s-channel single topquark production cross-section of 14.6 pb at the 95% confidence level. The fit gives a cross-section of sigma(s) = 5.0 +/- 4.3 pb, consistent with the Standard Model expectation.
Place, publisher, year, edition, pages
2015. Vol. 740, 222-242 p.
Higgs boson, Diphoton decay, t(t)over-barH, Top quark, Yukawa coupling, tH
IdentifiersURN: urn:nbn:se:kth:diva-160648DOI: 10.1016/j.physletb.2014.11.049ISI: 000347046200030ScopusID: 2-s2.0-84916883721OAI: oai:DiVA.org:kth-160648DiVA: diva2:790844
FunderKnut and Alice Wallenberg Foundation
QC 201502262015-02-262015-02-262015-02-26Bibliographically approved