Two-loop renormalization group equations for right-handed neutrino masses and phenomenological implications

TL;DR

This paper derives two-loop renormalization group equations for right-handed neutrino masses in an extended Standard Model, revealing significant quantum effects that influence neutrino masses and phenomenology.

Contribution

It provides the first calculation of two-loop beta functions for right-handed neutrino masses, highlighting their impact on neutrino mass predictions.

Findings

Two-loop effects can dominate the mass evolution of lighter right-handed neutrinos.

Quantum corrections significantly alter active neutrino masses in the seesaw mechanism.

Implications for low-energy neutrino phenomenology are substantial.

Abstract

We calculate the two-loop beta functions of the right-handed neutrino mass matrix in the Standard Model extended with right-handed neutrinos. We show that two-loop quantum effects induced by the heavier right-handed neutrinos can induce sizable contributions (sometimes dominant) to the physical masses of the lighter right-handed neutrinos. These effects can significantly affect the masses of the active neutrinos in the seesaw mechanism and the low energy phenomenology.