Higgs boson decay to charmonia via $c$-quark fragmentation

Abstract

We calculate the decay branching fractions of the Higgs boson to $J/\ddot{I}ˆ$ and $\hat{I}{\cdot }_c$ via the charm-quark fragmentation mechanism for the color-singlet and color-octet states in the framework of non-relativistic QCD. The decay rates are governed by the charm-quark Yukawa coupling, unlike the decay $H\to J/\ddot{I}ˆ+{\hat{I}}^3$, which is dominated by the $γ^*$-$J/\ddot{I}ˆ$ mixing. We find that the decay branching fractions can be about $2\times 10^{-5}$ for $H\to c\bar{c}+J/\ddot{I}ˆ$, and $6\times 10^{-5}$ for $H\to c\bar{c}+\hat{I}{\cdot }_c$. We comment on the perspective of searching for the Higgs boson to $J/\ddot{I}ˆ$ transition at the High-Luminosity LHC for testing the charm-quark Yukawa coupling.

Updated the discussion on the $y_c$ sensitivity, to be published on JHEP