Measurements of t t ¯ H Production and the CP Structure of the Yukawa Interaction between the Higgs Boson and Top Quark in the Diphoton Decay Channel

Date Issued
07-08-2020
Author(s)
Sirunyan, A. M.
Tumasyan, A.
Adam, W.
Ambrogi, F.
Bergauer, T.
Dragicevic, M.
Erö, J.
Escalante Del Valle, A.
Flechl, M.
Frühwirth, R.
Jeitler, M.
Krammer, N.
Krätschmer, I.
Liko, D.
Madlener, T.
Mikulec, I.
Rad, N.
Schieck, J.
Schöfbeck, R.
Spanring, M.
Waltenberger, W.
Wulz, C. E.
Zarucki, M.
Drugakov, V.
Mossolov, V.
Suarez Gonzalez, J.
Darwish, M. R.
De Wolf, E. A.
Di Croce, D.
Janssen, X.
Kello, T.
Lelek, A.
Pieters, M.
Rejeb Sfar, H.
Van Haevermaet, H.
Van Mechelen, P.
Van Putte, S.
Van Remortel, N.
Blekman, F.
Bols, E. S.
Chhibra, S. S.
D'Hondt, J.
De Clercq, J.
Lontkovskyi, D.
Lowette, S.
Marchesini, I.
Moortgat, S.
Python, Q.
Tavernier, S.
Van Doninck, W.
Van Mulders, P.
Beghin, D.
Bilin, B.
Clerbaux, B.
De Lentdecker, G.
Delannoy, H.
Dorney, B.
Favart, L.
Kalsi, A. K.
Moureaux, L.
Popov, A.
Postiau, N.
Starling, E.
Thomas, L.
Vander Velde, C.
Vanlaer, P.
Vannerom, D.
Cornelis, T.
Dobur, D.
Khvastunov, I.
Niedziela, M.
Roskas, C.
Skovpen, K.
Tytgat, M.
Verbeke, W.
Vermassen, B.
Vit, M.
Bruno, G.
Caputo, C.
David, P.
Delaere, C.
Delcourt, M.
Giammanco, A.
Lemaitre, V.
Prisciandaro, J.
Saggio, A.
Vischia, P.
Zobec, J.
Alves, G. A.
Correia Silva, G.
Hensel, C.
Moraes, A.
Belchior Batista Das Chagas, E.
Carvalho, W.
Chinellato, J.
Coelho, E.
Da Costa, E. M.
Da Silveira, G. G.
De Jesus Damiao, D.
De Oliveira Martins, C.
DOI
Abstract
The first observation of the tt¯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 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¯H process is measured to be σtt¯HBγγ=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 fCPHtt=0.00±0.33.
Volume
125