Search for Higgs boson decay to a charm quark-antiquark pair via $t\bar{tH}$ production

TL;DR

This paper reports a search for the Higgs boson decaying into charm quarks in association with top quarks using CMS data, setting limits on the Higgs-charm coupling and providing the first constraints in this channel.

Contribution

It presents the first search for $H\to c\bar{c}$ in $t\bar{t}H$ production and sets new upper limits on the Higgs-charm Yukawa coupling.

Findings

Observed $t\bar{t}H(H\to cc)$ rate limit is 7.8 times the SM prediction.

Combined analysis constrains the Higgs-charm Yukawa coupling modifier to below 3.5.

Measured $t\bar{t}H(H\to bb)$ event rate is consistent with the SM.

Abstract

In these proceedings, a search for the standard model Higgs boson decaying to a charm quark-antiquark pair, $H\to c\bar{c}$, produced in association with a top quark-antiquark pair ($t\bar{tH}$) is presented. The search is performed using proton-proton collision data collected by the CMS experiment at $s=13$ TeV, corresponding to an integrated luminosity of 138 fb$^{-1}$. The Higgs boson decay to a bottom quark-antiquark pair is measured simultaneously and the observed $t\bar{tH(H\to bb)}$ event rate relative to the standard model expectation is found to be $0.91^{+0.26}_{-0.22}$. The observed (expected) upper limit at 95\% confidence level (CL) for $t\bar{tH(H\to cc)}$ production is 7.8 (8.7) times the standard model prediction. Combined with a previous search for $H\to c\bar{c}$ via associated production with a W or Z boson, the observed (expected) 95\% CL interval on the Higgs-charm Yukawa coupling modifier, $\kappa_{c}$, is $\kappa_{c} < 3.5$ ($\kappa_{c} < 2.7$).