# Probing an additional bottom Yukawa coupling via $bg\to b A \to b Z H$ signature

## TL;DR

This paper proposes a method to directly search for an additional bottom Yukawa coupling in a two Higgs doublet model at the LHC, which could have implications for electroweak baryogenesis.

## Contribution

It introduces a novel search strategy for the extra bottom Yukawa coupling $
ho_{bb}$ via specific processes at the LHC, highlighting potential discovery prospects.

## Key findings

- The $bg o b A o b Z H$ process could be discovered with ~300 fb$^{-1}$ at the LHC for $m_A ext{ around } 300$ GeV.
- The $gg o b ar b A o b ar b Z H$ process may be observable at the high luminosity LHC.
- Discovery of $
ho_{bb}$ could provide insights into electroweak baryogenesis.

## Abstract

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 the nature. The two Higgs doublet model without a discrete $Z_2$ symmetry allows the possibility of additional bottom Yukawa coupling $\rho_{bb}$. We show that $\rho_{bb}$ can be searched directly at the LHC via $bg\to b A \to b Z H$ and $gg \to b \bar b A \to b \bar b Z H$ processes, where $A$ and $H$ are the CP-odd and CP-even scalars respectively. We find that the $bg\to b A \to b Z H$ process could be discovered with $\sim300$ fb$^{-1}$ integrated luminosity if $ m_A \sim 300$ GeV, while the latter process may emerge in the high luminosity LHC (HL-LHC) data. A discovery might touch upon the parameter space required for the electroweak baryogenesis.