Early Universe effective theories: The Soft Leptogenesis and R-Genesis Cases

TL;DR

This paper develops an effective theory for soft leptogenesis at high temperatures, highlighting the dominant role of R-genesis in baryon asymmetry generation and showing it can be highly efficient even without thermal corrections.

Contribution

It introduces a comprehensive effective theory for soft leptogenesis at T>10^7 GeV, emphasizing the significance of R-genesis and providing general Boltzmann equations applicable across temperature regimes.

Findings

R-genesis can produce a baryon asymmetry up to two orders of magnitude larger than previous estimates.

A sizeable baryon asymmetry can be generated without thermal corrections to CP asymmetries.

The paper presents generalized Boltzmann equations valid for all temperature regimes.

Abstract

We discuss the effective theory appropriate for studying soft leptogenesis at temperatures T>10^7 GeV. In this regime, the main source of the B-L asymmetry is the CP asymmetry of a new anomalous R-charge that couple to generalized anomalous electroweak processes. Baryogenesis thus occurs mainly through R-genesis, and with an efficiency that can be up to two orders of magnitude larger than in usual estimates. Contrary to common belief, a sizeable baryon asymmetry is generated also when thermal corrections to the CP asymmetries in sneutrino decays are neglected which, in soft leptogenesis, implyes vanishing lepton-flavour CP asymmetries. We present general Boltzmann equations for soft leptogenesis that are valid in all temperature regimes.