In the most general two-Higgs-doublet model with an approximate family symmetry and $\mathrm{CP}$ violation originating solely from the relative phase of two vacuum expectation values, $\mathrm{CP}$ asymmetry in the decay $b\to s\gamma$ may arise from the $\mathrm{CP}$ violation of the charged Higgs boson interactions with fermions. This asymmetry may be larger than in the standard model and can lie between ${10}^{-2\mathrm{}}$ and ${10}^{-1\mathrm{}}$. The decay rate of $b\to s\gamma$ is allowed to be smaller or larger than in the standard model.

• Received 28 July 1994

DOI:https://doi.org/10.1103/PhysRevLett.73.2809