Generation-changing processes in two-Higgs-doublet models

The calculations for the neutral-current generation-changing vertices B¯γA and B¯ZA in two-Higgs-doublet models are presented. The results are illustrated with a discussion on enhancements to the rare decays μ→eγ, ν’→νγ, and b→sγ. For b→sγ, we obtain very stringent bounds on the charged Higgs couplings. They are better than the bounds obtained from the $B_S^0$-$B_L^0$ mass difference. The predicted branching ratios B(b→sγ) are presented.