Affleck-Dine Cogenesis of Baryon and Dark Matter

TL;DR

This paper presents a unified mechanism using the Affleck-Dine process for generating both baryon asymmetry and dark matter in the universe, linking cosmic evolution, particle physics, and observational constraints.

Contribution

It introduces a novel cogenesis model where an Affleck-Dine field simultaneously explains baryon asymmetry and dark matter abundance, incorporating a gauged B-L portal and inflationary dynamics.

Findings

The model successfully generates the observed baryon asymmetry and dark matter density.

It predicts light DM and B-L gauge bosons in the few GeV range, within experimental reach.

Remaining parameter space is testable by upcoming laboratory and cosmological experiments.

Abstract

We propose a mechanism for cogenesis of baryon and dark matter (DM) in the universe via the Affleck-Dine (AD) route. An AD field which breaks the lepton number symmetry, leads to the generation of lepton asymmetry by virtue of its cosmic evolution, which then gets transferred into lepton and dark sectors. While the lepton asymmetry gets converted into baryon asymmetry via sphalerons, the dark sector asymmetry leads to the final DM abundance with the symmetric part being annihilated away due to resonantly enhanced annihilation, which we choose to be provided by a gauged $B-L$ portal. Stringent constraints from DM direct detection forces DM and $B-L$ gauge boson masses to be light, in the few GeV ballpark. While a large portion of the model parameter space is already ruled out, the remaining parameter space is within sensitivity of laboratory as well as cosmology based experiments. The AD field also plays the role of inflaton with the required dynamics by virtue of its non-minimal coupling to gravity, consistent with observations.