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

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 rho(bb). We show that rho(bb) can be searched directly at the LHC via the bg -> bA -> bZH and gg -> b (b) over barA -> b (b) over bar bZH processes, where A and H are the CP-odd and CP-even scalars, respectively. We find that the bg -> bA -> bZH process could be discovered with similar to 300 fb(-1) integrated luminosity if m(A) similar to 300 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.