Mass-derivative relations and unitarity constraints for $CP$ asymmetries at finite temperature

TL;DR

This paper explores how $CP$ asymmetries in leptogenesis are constrained by $CPT$ and unitarity at finite temperature, highlighting the impact of quantum effects and higher-order corrections on kinetic theory.

Contribution

It formulates $CPT$ and unitarity constraints for $CP$ asymmetries in thermal leptogenesis, incorporating quantum effects and higher-order corrections.

Findings

Quantum effects significantly influence $CP$ asymmetries.

Higher-order perturbative corrections induce quantum effects in kinetic theory.

Thermal mass and quantum statistics modify reaction rates.

Abstract

Within the seesaw type-I leptogenesis, we formulate $CPT$ and unitarity constraints for the equilibrium reaction rate $CP$ asymmetries and consider thermal mass and quantum statistics. We demonstrate that including higher-order perturbative corrections in the classical Boltzmann equation remarkably induces quantum effects into the kinetic theory.