# Fermion number violating effects in low scale leptogenesis

## TL;DR

This paper develops kinetic equations to describe fermion number violating effects in low-scale leptogenesis, identifying conditions that could enhance lepton asymmetry and dark matter production via sterile neutrinos.

## Contribution

It introduces new kinetic equations that incorporate previously neglected fermion number violating effects in low-scale leptogenesis models.

## Key findings

- Derived kinetic equations including fermion number violation.
- Identified HNL mass domain for efficient lepton asymmetry generation.
- Potentially boosts sterile neutrino dark matter production.

## Abstract

The existence of baryon asymmetry and dark matter in the Universe may be related to CP-violating reactions of three heavy neutral leptons (HNLs) with masses well below the Fermi scale. The dynamical description of the lepton asymmetry generation, which is the key ingredient of baryogenesis and of dark matter production, is quite complicated due to the presence of many different relaxation time scales and the necessity to include quantum-mechanical coherent effects in HNL oscillations. We derive kinetic equations accounting for fermion number violating effects missed so far and identify one of the domains of HNL masses that can potentially lead to large lepton asymmetry generation boosting the sterile neutrino dark matter production.