Leptogenesis in crossing and runaway regimes

Understand

We study the impact of effective thermal masses and widths on resonant leptogenesis.

• We identify two distinct possibilities which we refer to as crossing and runaway regimes.
• In the runaway regime the mass difference grows monotonously with temperature, whereas it initially decreases in the crossing regime, such that the effective masses become equal at some temperature.
• Following the conventional logic the source of the asymmetry would vanish in the latter case.