Purely Flavored Leptogenesis

TL;DR

This paper presents a leptogenesis model where baryon asymmetry arises solely from flavor effects, enabling successful leptogenesis at TeV scales and considering experimental constraints on lepton flavor violation.

Contribution

It introduces a leptogenesis scenario with vanishing total CP asymmetries, emphasizing flavor effects as the sole source of baryon asymmetry, and demonstrates viability at low energy scales.

Findings

Successful leptogenesis at TeV scale.

Lepton flavor asymmetries drive baryon asymmetry.

Constraints from lepton flavor violating decays are analyzed.

Abstract

We study a model for leptogenesis in which the total CP asymmetries in the decays and scatterings involving the SU(2) singlet seesaw neutrinos $N_\alpha$ vanish ($\epsilon_{N_\alpha}=0$). Leptogenesis is possible due to non-vanishing CP violating lepton flavor asymmetries, realizing a situation in which the baryon asymmetry is due exclusively to flavor effects. We study the production of a net lepton asymmetry by solving the Boltzmann equations specific to this model, and we show that successful leptogenesis can be obtained at a scale as low as the TeV. We also discuss constraints on the model parameter space arising from current experimental upper limits on lepton flavor violating decays.