$1 \leftrightarrow 2$ Processes of a Sterile Neutrino Around Electroweak Scale in the Thermal Plasma

TL;DR

This paper calculates the processes of a sterile neutrino in the thermal plasma near the electroweak scale using the Goldstone equivalence gauge, with implications for leptogenesis.

Contribution

It introduces a method to compute sterile neutrino processes around the electroweak scale in the thermal plasma, applying the Goldstone equivalence gauge for the first time in this context.

Findings

Thermal averaged effective width is continuous around the cross-over.

Method applied to preliminary leptogenesis calculations.

Sterile neutrino processes characterized at electroweak scale.

Abstract

In this paper, we will apply the Goldstone equivalence gauge to calculate the $1 \leftrightarrow 2$ processes of a sterile neutrino in the thermal plasma below the standard model (SM) critical temperature $T_c \approx 160 \text{ GeV}$. The sterile neutrino's mass is around the electroweak scale $50 \text{ GeV} \leq m_N \leq 200 \text{ GeV}$, and the acquired thermal averaged effective width $\bar{\Gamma}_{\text{tot}}$ is continuous around the cross-over. We will also apply our results to perform a preliminary calculation of the leptogenesis.