Fermion masses and the UV cutoff of the minimal realistic SU(5) model

Abstract

We investigate the predictions for fermion masses in the minimal realistic nonsupersymmetric SU(5) model with the standard model matter content. The possibility to achieve b-tau unification is studied taking into account all relevant effects. In addition, we show how to establish an upper bound on the ultraviolet cutoff Lambda of the theory which is compatible with the Yukawa couplings at the grand unified scale and proton decay. We find Lambda ~= 10^(17) GeV, to be considered a conservative upper bound on the cutoff. We also provide up-to-date values of all the fermions masses at the electroweak scale.