Quantum Boltzmann equations in resonant leptogenesis

TL;DR

This paper derives quantum Boltzmann equations incorporating memory effects for leptogenesis, revealing a time-dependent CP asymmetry that significantly alters predictions in resonant leptogenesis scenarios.

Contribution

It introduces a non-equilibrium quantum field theory approach to leptogenesis, accounting for memory effects and time-dependent CP asymmetry, which were neglected in previous models.

Findings

Memory effects lead to a time-dependent CP asymmetry.

Quantitative differences compared to traditional approaches.

Implications for resonant leptogenesis and Lepton Flavour Violation.

Abstract

The quantum Boltzmann equations relevant for leptogenesis, obtained using non-equilibrium quantum field theory, are described. They manifest memory effects leading to a time-dependent CP asymmetry which depends upon the previous history of the system. This result is particularly relevant in resonant leptogenesis where the asymmetry is generated by the decays of nearly mass-degenerate right-handed neutrinos. The impact of the non-trivial time evolution of the CP asymmetry is discussed either in the generic resonant leptogenesis scenario or in the more specific Minimal Lepton Flavour Violation framework. Significant quantitative differences arise with respect to the usual approach in which the time dependence of the CP asymmetry is neglected.