Simultaneous probe of the charm and bottom quark Yukawa couplings using $\mathrm{t}\bar{\mathrm{t}}$H events

Abstract

A search for the standard model Higgs boson decaying to a charm quark-antiquark pair, H $\to$ $\mathrm{c}\bar{\mathrm{c}}$, produced in association with a top quark-antiquark pair ($\mathrm{t}\bar{\mathrm{t}}$H) is presented. The search is performed with data from proton-proton collisions at $\sqrt{s}$ = 13 TeV, corresponding to an integrated luminosity of 138 fb${}^{-1}$. Advanced machine learning techniques are employed for jet flavor identification and event classification. The Higgs boson decay to a bottom quark-antiquark pair is measured simultaneously and the observed $\mathrm{t}\bar{\mathrm{t}}$H (H $\to$ $\mathrm{b}\bar{\mathrm{b}}$) event rate relative to the standard model expectation is 0.91 ${}_{-0.22}^{+0.26}$. The observed (expected) upper limit on the product of production cross section and branching fraction $\ddot{I}ƒ$($\mathrm{t}\bar{\mathrm{t}}$H) $\mathcal{B}$(H $\to$ $\mathrm{c}\bar{\mathrm{c}}$) is 0.11 (0.13) pb at 95% confidence level, corresponding to 7.8 (8.7) times the standard model prediction. When combined with the previous search for H $\to$ $\mathrm{c}\bar{\mathrm{c}}$ via associated production with a W or Z boson, the observed (expected) 95% confidence interval on the Higgs-charm Yukawa coupling modifier, $\hat{I}{º}_{\mathrm{c}}$, is $|\hat{I}{º}_{\mathrm{c}}|$ $<$ 3.5 (2.7), the most stringent constraint to date.

Replaced with the published version. Added the journal reference and the DOI. All the figures and tables, including additional supplementary figures, can be found at http://cms-results.web.cern.ch/cms-results/public-results/publications/HIG-24-018 (CMS Public Pages)