A Minimal Approach to Baryogenesis via Affleck-Dine and Inflaton Mass Terms

TL;DR

This paper proposes a minimal baryogenesis mechanism where a complex inflaton condensate generates the universe's matter-antimatter asymmetry through B-violating inflaton mass terms, avoiding fine-tuning.

Contribution

It introduces a novel minimal approach using inflaton mass terms for Affleck-Dine baryogenesis, simplifying the dynamics compared to traditional methods.

Findings

The asymmetry oscillates and is naturally reduced to observed levels.

The mechanism is compatible with various inflation models.

It avoids the tuning issues of conventional Affleck-Dine baryogenesis.

Abstract

We present a minimal approach to the generation of the baryon ($B$) asymmetry of the Universe, in which the asymmetry is generated in a complex inflaton condensate via $B$-violating quadratic inflaton potential terms using the Affleck-Dine (AD) mechanism. We show that the $B$-violating quadratic mass terms create an oscillating asymmetry in the complex inflaton condensate at late times. The final asymmetry transferred to the Standard Model sector at reheating is naturally reduced to the magnitude of the observed $B$ asymmetry by the effect of averaging over the $B$ oscillations. This approach to baryogenesis can easily be realised in a wide range of inflation models. We also show that AD baryogenesis via inflaton mass terms is free of the tuning of field dynamics required by the conventional AD mechanism.