Abstract : The first measurement of the cross section ratio sigma(t t-bar b b-bar) / sigma(t t-bar jj) is presented using a data sample corresponding to an integrated luminosity of 19.6 inverse femtobarns collected in pp collisions at sqrt(s) = 8 TeV with the CMS detector at the LHC. Events with two leptons (e or mu) and four reconstructed jets, including two identified as b quark jets, in the final state are selected. The ratio is determined for a minimum jet transverse momentum pt of both 20 and 40 GeV. The measured ratio is 0.022 +/- 0.003 (stat) +/- 0.005 (syst) for pt > 20 GeV. The absolute cross sections sigma(t t-bar b b-bar) and sigma(t t-bar jj) are also measured. The measured ratio for pt > 40 GeV is compatible with a theoretical quantum chromodynamics calculation at next-to-leading order.
http://hal.in2p3.fr/in2p3-01089360
Contributeur : Dominique Girod
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Soumis le : lundi 1 décembre 2014 - 15:42:26
Dernière modification le : mercredi 23 janvier 2019 - 14:38:46
V. Khachatryan, M. Besancon, F. Couderc, M. Dejardin, D. Denegri, et al.. Measurement of the cross section ratio sigma(t t-bar b b-bar) / sigma(t t-bar jj) in pp collisions at sqrt(s) = 8 TeV. Physics Letters B, Elsevier, 2015, 746, pp.132-153. 〈10.1016/j.physletb.2015.04.060〉. 〈in2p3-01089360〉
