Thermal right-handed neutrino self-energy in the non-relativistic regime

TL;DR

This paper calculates the next-to-leading order thermal self-energy matrix for heavy right-handed neutrinos in the non-relativistic regime, aiding leptogenesis models by providing detailed flavor transition and decay information.

Contribution

It provides the first resummed 2-loop level thermal self-energy matrix for right-handed neutrinos in the Standard Model, including flavor transitions and decay processes.

Findings

Resummed 2-loop thermal self-energy matrix derived

Describes flavor transitions and inclusive decays

Applicable to leptogenesis in the strong washout regime

Abstract

Recently the issue of radiative corrections to leptogenesis has been raised. Considering the "strong washout" regime, in which OPE-techniques permit to streamline the setup, we report the thermal self-energy matrix of heavy right-handed neutrinos at NLO (resummed 2-loop level) in Standard Model couplings. The renormalized expression describes flavour transitions and "inclusive" decays of chemically decoupled right-handed neutrinos. Although CP-violation is not addressed, the result may find use in existing leptogenesis frameworks.