In a general two-Higgs-doublet model (2HDM), without the {\it ad hoc} discrete symmetries to prevent tree-level flavor-changing-neutral currents, an extra phase angle in the charged-Higgs-fermion coupling is allowed. We show that the charged-Higgs amplitude interferes destructively or constructively with the standard model amplitude depending crucially on this phase angle. The popular model I and II are special cases of our analysis. As a result of this phase angle the severe constraint on the charged-Higgs boson mass imposed by the inclusive rate of b→sγ from CLEO can be relaxed. We also examine the effects of this phase angle on the neutron electric dipole moment. Furthermore, we also discuss other constraints on the charged-Higgs-fermion couplings coming from measurements of B0−B0ˉ mixing, ρ0, and Rb.
@article{arxiv.hep-ph/9811235,
title = {Phase Effect of A General Two-Higgs-Doublet Model in $b\to s\gamma$},
author = {David Bowser-Chao and Kingman Cheung and Wai-Yee Keung},
journal= {arXiv preprint arXiv:hep-ph/9811235},
year = {2009}
}