LHC Seminar

Measurement of $ttH$ production in the diphoton channel and observation of heavy triboson production with the CMS detector in pp collisions at $\sqrt s = 13\ \mathrm{TeV}$

by Hannsjorg Weber (Fermi National Accelerator Lab. (US)), Julie Malcles (Université Paris-Saclay (FR))


We present two recent CMS results based on the full dataset of LHC Run 2. Decays of the Higgs boson to photons have been used to investigate the ttH process. A significance of 6.6 s.d. is achieved in this single channel. The product of cross section and branching fraction is measured to be $1.56^{+0.34}_{-0.32}$ fb. The sample is used to investigate the CP structure the top Yukawa coupling, and a pure CP-odd structure is excluded at 3.2. s.d. . We also present the first observation of production of three massive vector bosons. Events with 3 - 6 isolated electrons or muons, or 2 same-sign leptons and 1 or 2 jets in the final state have been used to search for $WWW$, $WWZ$, $WZZ$, and $ZZZ$ production. The combined significance reaches 5.7 s.d., with evidence for the individual $WWW$ and $WWZ$ channels. The combined signal strength is measured to be $1.02^{+0.26}_{-0.23}$.

Organized by

M. Mangano, M. Pepe-Altarelli, G. Unal

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