A comprehensive phenomenological analysis of a two Higgs doublet model, with flavor-changing scalar currents at the tree level, called model III, is presented. Constraints from existing experimental information especially on $\Delta F=2\mathrm{}$ processes are systematically incorporated. Constraints emerging from rare $B$ decays, $Z\to b\overline{b}$, and the $\rho$ parameter are also examined. Experimental implications for $e^{+}{e}^{-}\left({\mu }^{+}{\mu }^{-}\right)\to t\overline{c}+\overline{t}c$, $t\to c\gamma \mathrm{}(Z,g),\hspace{0.5em}{D}^0-{\overline{D}}^0$, and $B_s^0-{\overline{B}}_s^0$ oscillations, and for $e^{+}{e}^{-}\mathrm{}\left(Z\right)\mathrm{}\to b\overline{s}+\overline{b}s$ are investigated and experimental effort towards these is stressed. We also emphasize the importance of clarifying the experimental issues pertaining to $Z\to b\overline{b}$.

• Received 6 September 1996

DOI:https://doi.org/10.1103/PhysRevD.55.3156