Systematic approach to Delta L=1 processes in thermal leptogenesis

TL;DR

This paper develops a quantum-field-theoretic framework for calculating Delta L=1 processes in thermal leptogenesis, incorporating quantum-statistical effects and medium corrections to improve the accuracy of lepton asymmetry predictions.

Contribution

It introduces a systematic quantum-field-theoretic approach to compute CP-violating and washout reaction densities in leptogenesis, including higher-order corrections and medium effects.

Findings

Quantum-corrected Boltzmann equations derived

Reaction densities numerically compared to conventional results

Medium corrections significantly impact lepton asymmetry calculations

Abstract

In this work we study the contribution to leptogenesis from Delta L=1 decay and scattering processes mediated by the Higgs with quarks in the initial and final states using the formalism of non-equilibrium quantum field theory. Starting from fundamental equations for correlators of the quantum fields we derive quantum-corrected Boltzmann and rate equations for the total lepton asymmetry improved in that they include quantum-statistical effects and medium corrections to the quasiparticle properties. To compute the collision term we take into account one- and two-loop contributions to the lepton self-energy and use the extended quasiparticle approximation for the Higgs two-point function. The resulting CP-violating and washout reaction densities are numerically compared to the conventional ones.