Effects of Large CP Phases on the Proton Lifetime in Supersymmetric Unification

Abstract

The effects of large CP violating phases arising from the soft SUSY breaking parameters on the proton lifetime are investigated in supersymmetric grand unified models. It is found that the CP violating phases can reduce as well as enhance the proton lifetime depending on the part of the parameter space one is in. Modifications of the proton lifetime by as much as a factor of 2 due to the effects of the CP violating phases are seen. The largest effects arise for the lightest sparticle spectrum in the dressing loop integrals and the effects decrease with the increasing scale of the sparticle masses. An analysis of the uncertainties in the determination of the proton life time due to uncertainties in the quark masses and in the other input data is also given. These results are of import in the precision predictions of the proton lifetime in supersymmetric unification both in GUT and in string models when the soft SUSY breaking parameters are complex.