Lepto-axiogenesis in minimal SUSY KSVZ model

TL;DR

This paper explores lepto-axiogenesis within a minimal supersymmetric KSVZ axion model, analyzing the dynamics of the PQ field and its implications for baryon asymmetry, dark matter, and neutrino physics.

Contribution

It introduces a semi-analytical method to track PQ field dynamics, including thermal effects, and demonstrates successful baryon asymmetry generation in specific parameter regimes.

Findings

Baryon asymmetry explained for PQ mass around 10^6 GeV.

Effective neutrino number consistent with observations.

Dark matter density from axions and neutralinos matches cosmological data.

Abstract

We study the lepto-axiogenesis scenario in the minimal supersymmetric KSVZ axion model. Only one Peccei-Quinn (PQ) field and vector-like fields are introduced besides the MSSM with the type-I see-saw mechanism. The PQ field is stabilized by the radiative correction induced by the Yukawa couplings with the vector-like fields introduced in the KSVZ model. We develop a way to follow the dynamics of the PQ field, in particular we found a semi-analytical solution which describes the rotational motion under the logarithmic potential with including the thermalization effect via the gluon scattering which preserves the PQ symmetry. Based on the solution, we studied the baryon asymmetry, the effective number of neutrino, and the dark matter density composed of the axion and the neutralino. We found that the baryon asymmetry is successfully explained when the mass of PQ field is $\mathcal{O}({10^6~\mathrm{GeV}})$ ($\mathcal{O}({10^5~\mathrm{GeV}})$) with the power of the PQ breaking term being $10$ ($8$).