Probing an additional bottom Yukawa coupling via bg→bA→bZH signature

OpenAlex lv

The recent discovery of the bottom quark Yukawa coupling ($hbb$) of the 125 GeV scalar motivates one to search for extra bottom Yukawa coupling that may exist in nature. The two Higgs doublet model without a discrete ${Z}_{2}$ symmetry allows the possibility of additional bottom Yukawa coupling ${\ensuremath{\rho}}_{bb}$. We show that ${\ensuremath{\rho}}_{bb}$ can be searched directly at the LHC via the $bg\ensuremath{\rightarrow}bA\ensuremath{\rightarrow}bZH$ and $gg\ensuremath{\rightarrow}b\overline{b}A\ensuremath{\rightarrow}b\overline{b}ZH$ processes, where $A$ and $H$ are the $CP$-odd and $CP$-even scalars, respectively. We find that the $bg\ensuremath{\rightarrow}bA\ensuremath{\rightarrow}bZH$ process could be discovered with $\ensuremath{\sim}300\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ integrated luminosity if ${m}_{A}\ensuremath{\sim}300\text{ }\text{ }\mathrm{GeV}$, while the latter process may emerge in the high luminosity LHC (HL-LHC) run. A discovery might touch upon the parameter space required for the electroweak baryogenesis.