Leptogenesis via Inflaton Mass Terms in Non-Minimally Coupled Inflation

TL;DR

This paper proposes a minimal leptogenesis model where lepton number-violating mass terms in a non-minimally coupled inflaton generate lepton asymmetry, which is transferred to the Standard Model via inflaton decay, with observable implications for baryon isocurvature fluctuations and gravitational waves.

Contribution

It introduces a novel leptogenesis mechanism using inflaton mass terms in non-minimally coupled inflation, linking baryogenesis with inflationary observables.

Findings

Lepton asymmetry generated via the Affleck-Dine mechanism in the inflaton field.

Baryon isocurvature fluctuations are observable in metric inflation but negligible in Palatini inflation.

Reheating temperatures compatible with detectable primordial gravitational waves.

Abstract

We consider a model of baryogenesis based on adding lepton number-violating quadratic mass terms to the inflaton potential of a non-minimally coupled inflation model. The $L$-violating mass terms generate a lepton asymmetry in a complex inflaton field via the mass term Affleck-Dine mechanism, which is transferred to the Standard Model (SM) sector when the inflaton decays to right-handed (RH) neutrinos. The model is minimal in that it requires only the SM sector, RH neutrinos, and a non-minimally coupled inflaton sector. We find that baryon isocurvature fluctuations can be observable in metric inflation but are negligible in Palatini inflation. The model is compatible with reheating temperatures that may be detectable in the observable primordial gravitational waves predicted by metric inflation.