Low-energy effects of Charged Higgs with general Yukawa couplings

Abstract

We study a model with two Higgs doublets where FCNC are allowed at tree-level. In this model, the interactions of charged Higgs with fermions ($H^{\pm }f\overline{f^{\prime }}$), include a term that is not proportional to the fermion masses, which we constraint using the following low-energy processes: i) tau decays ($\tau \to {\nu }_{\tau }e{\nu }_e,{\nu }_{\tau }\mu {\nu }_{\mu },{\nu }_{\tau }\pi$), ii) leptonic decays of pseudoscalar mesons ($\pi ,K\to \ell {\nu }_{\ell }$) and iii) semileptonic b-decays. With these constraints it is possible to make predictions; we illustrate this by presenting the rates for the (FCNC) decay $c\to u+\gamma$, the (second class-current) decay $\tau \to {\nu }_{\tau }+\eta \pi$, and also the theoretical value of the neutron life-time.

22 pages, phyzz, 1 figure upon request, corrected version of paper published in Phys. Rev. D51, 5263 (1995)