par Sirunyan, A.M.;Beghin, Diego ;Bilin, Bugra ;Clerbaux, Barbara ;De Lentdecker, Gilles ;Delannoy, Hugo ;Dorney, Brian ;Favart, Laurent ;Kalsi, Amandeep Kaur ;Moureaux, Louis ;Popov, Andrey ;Postiau, Nicolas ;Thomas, Laurent ;Vander Velde, Catherine ;Vanlaer, Pascal ;Vannerom, David ;Malara, Andrea ; [et al.]
Référence Physical review letters, 125, 6, 061801
Publication Publié, 2020-10-01
Référence Physical review letters, 125, 6, 061801
Publication Publié, 2020-10-01
Article révisé par les pairs
Résumé : | The first observation of the tt[over ¯]H process in a single Higgs boson decay channel with the full reconstruction of the final state (H→γγ) is presented, with a significance of 6.6 standard deviations (σ). The CP structure of Higgs boson couplings to fermions is measured, resulting in an exclusion of the pure CP-odd structure of the top Yukawa coupling at 3.2σ. The measurements are based on a sample of proton-proton collisions at a center-of-mass energy sqrt[s]=13 TeV collected by the CMS detector at the LHC, corresponding to an integrated luminosity of 137 fb^{-1}. The cross section times branching fraction of the tt[over ¯]H process is measured to be σ_{tt[over ¯]H}B_{γγ}=1.56_{-0.32}^{+0.34} fb, which is compatible with the standard model prediction of 1.13_{-0.11}^{+0.08} fb. The fractional contribution of the CP-odd component is measured to be f_{CP}^{Htt}=0.00±0.33. |