Moduli induced cogenesis of baryon asymmetry and dark matter

TL;DR

This paper proposes a string-inspired model where moduli decay produces both baryon asymmetry and dark matter simultaneously at low reheating temperatures, explaining cosmic coincidence without violating baryon number.

Contribution

It introduces a novel cogenesis mechanism involving moduli decay in a string theory context, linking baryon asymmetry and dark matter production with specific superfield interactions.

Findings

The model successfully reproduces observed baryon asymmetry.

It predicts an asymmetric dark matter component with correct abundance.

The mechanism naturally explains the cosmic coincidence problem.

Abstract

We study a cogenesis mechanism in which the observed baryon asymmetry of the universe and the dark matter abundance can be produced simultaneously at low reheating temperature without violating baryon number in the fundamental vertex. In particular, we consider a model which could be realized in the context of type IIB large volume string compactifications. The matter superfields in this model include additional pairs of color triplet and singlet superfields in addition to the Minimal Supersymmetric Standard Model (MSSM) superfields. Assuming that the mass of the additional singlet fermions is O(GeV) and color triplet fermions is O(TeV), we show that the modulus dominantly decays into the additional color triplet superfields. After soft supersymmetry (SUSY) breaking, the lightest eigenstate of scalar component of color triplet superfield further decays into fermionic component of singlet superfield and quarks without violating baryon number. Assuming R-parity conservation, it follows that the singlet superfield will not further decay into the SM particles and therefore it can be considered as a stable asymmetric dark matter (ADM) component. We find that the decay of the lightest eigenstate of scalar component of color triplet superfield gives the observed baryon asymmetry in the visible sector, an asymmetric dark matter component with the right abundance and naturally explains cosmic coincidence.