Lepton-mediated electroweak baryogenesis

TL;DR

This paper examines how tau and bottom Yukawa interactions influence electroweak baryogenesis in supersymmetric models, revealing their significant role and proposing a lepton-mediated scenario that alters previous baryon asymmetry calculations.

Contribution

It demonstrates the importance of tau and bottom Yukawa couplings in electroweak baryogenesis and introduces a new lepton-mediated scenario with revised analytic formulas.

Findings

Tau and bottom Yukawa interactions are significant in baryogenesis.

The proposed scenario yields opposite baryon asymmetry signs.

New analytic formulas differ from previous literature.

Abstract

We investigate the impact of the tau and bottom Yukawa couplings on the transport dynamics for electroweak baryogenesis in supersymmetric extensions of the Standard Model. Although it has generally been assumed in the literature that all Yukawa interactions except those involving the top quark are negligible, we find that the tau and bottom Yukawa interaction rates are too fast to be neglected. We identify an illustrative "lepton-mediated electroweak baryogenesis" scenario in which the baryon asymmetry is induced mainly through the presence of a left-handed leptonic charge. We derive analytic formulae for the computation of the baryon asymmetry that, in light of these effects, are qualitatively different from those in the established literature. In this scenario, for fixed CP-violating phases, the baryon asymmetry has opposite sign compared to that calculated using established formulae.