Abstract : The consistency of the spin correlation strength in top quark pair production with the standard model (SM) prediction is tested in the muon+jets final state. The events are selected from pp collisions, collected by the CMS detector, at a centre-of-mass energy of 8 TeV, corresponding to an integrated luminosity of 19.7 inverse-femtobarns. The data are compared with the expectation for the spin correlation predicted by the SM and with the expectation of no correlation. Using a template fit method, the fraction of events that show SM spin correlations is measured to be 0.72 +/- 0.08 (stat) +0.15 -0.13 (syst), representing the most precise measurement of this quantity in the lepton+jets final state to date.
http://hal.in2p3.fr/in2p3-01231357
Contributeur : Sylvie Flores
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Soumis le : vendredi 20 novembre 2015 - 07:15:35
Dernière modification le : jeudi 7 février 2019 - 15:17:44
V. Khachatryan, M. Besançon, F. Couderc, M. Dejardin, D. Denegri, et al.. Measurement of spin correlations in t-tbar production using the matrix element method in the muon+jets final state in pp collisions at sqrt(s) = 8 TeV. Physics Letters B, Elsevier, 2016, 758, pp.321-346. 〈10.1016/j.physletb.2016.05.005〉. 〈in2p3-01231357〉