Bottom-tau unification by neutrinos in a nonsupersymmetric SU(5) model

TL;DR

This paper demonstrates that in a non-supersymmetric SU(5) model, bottom quark and tau lepton Yukawa couplings can be unified by incorporating right-handed neutrinos and analyzing their renormalization group evolution.

Contribution

It introduces a method to achieve bottom-tau unification in a non-supersymmetric SU(5) framework with arbitrary right-handed neutrinos and explores their mass bounds.

Findings

Unification of bottom and tau Yukawa couplings is possible in this model.

The upper bound on right-handed neutrino mass is approximately 10^{14.1} GeV.

Unification conditions are satisfied at a GUT scale of 10^{15.5} GeV.

Abstract

We show that Yukawa couplings of bottom quarks and tau leptons can be unified in a non-supersymmetric SU(5) model. We introduce an arbitrary number of right-handed neutrinos. Their masses and Yukawa couplings that satisfy the unification condition by renormalization group evolution are shown. In the case that the grand unification scale is $10^{15.5}$GeV and three right-handed neutrinos have the same mass, the upper bound on their mass is $\sim 10^{14.1}$GeV.