Effective Lagrangian for Charged Higgs Couplings

The effective Lagrangian including one loop corrections is deduced for the couplings of the charged Higgs with quarks and leptons, and with charginos and neutralinos. The effect of the one loop corrections is found to be quite significant in a number of sectors. The effective Lagrangian is then used to analyze the decay of the charged Higgs into a number of decay channels. Specifically we consider the decay of $H^+(H^-)$ into the decay modes $t\bar b$ ($\bar t b$), $\bar\tau\nu_{\tau}$ ($\tau \bar \nu_{\tau}$), and $\chi_i^+\chi_j^0(\chi_i^-\chi_j^0)$ (i=1,2; j=1-4). The loop corrections to these decay modes are also found to be quite significant lying in the range 20-30% in significant regions of the parameter space of the SUGRA model. The effects of CP phases on the effective Lagrangian and on the branching ratios are also analysed and these effects found to be important.