Leptogenesis in the Universe

TL;DR

Leptogenesis explains the universe's matter-antimatter asymmetry through lepton asymmetry generated by heavy sterile neutrino decays, with various effects and models enhancing its viability.

Contribution

This paper reviews the motivations, mechanisms, and variations of leptogenesis, including effects like lepton flavors, spectator processes, and supersymmetric scenarios.

Findings

Leptogenesis is a compelling baryogenesis mechanism.

Multiple effects influence leptogenesis outcomes.

Supersymmetric models offer alternative leptogenesis pathways.

Abstract

Leptogenesis is a class of scenarios in which the cosmic baryon asymmetry originates from an initial lepton asymmetry generated in the decays of heavy sterile neutrinos in the early Universe. We explain why leptogenesis is an appealing mechanism for baryogenesis. We review its motivations, the basic ingredients, and describe subclasses of effects, like those of lepton flavours, spectator processes, scatterings, finite temperature corrections, the role of the heavier sterile neutrinos and quantum corrections. We then address leptogenesis in supersymmetric scenarios, as well as some other popular variations of the basic leptogenesis framework.