Bino-driven Electroweak Baryogenesis with highly suppressed Electric Dipole Moments

TL;DR

This paper demonstrates that bino-driven electroweak baryogenesis in the MSSM can occur without large electric dipole moments, challenging previous assumptions about their incompatibility and identifying a viable scenario with a light stop.

Contribution

It introduces a bino-Higgsino CP-violation mechanism that enables successful electroweak baryogenesis without large EDMs, expanding the viable parameter space in MSSM.

Findings

Bino-Higgsino CP-violation can produce baryogenesis without large EDMs.

Bino-driven scenario with a light stop is most phenomenologically viable.

Weakens the link between EDM constraints and electroweak baryogenesis.

Abstract

It is conventional wisdom that successful electroweak baryogenesis in the Minimal Supersymmetric extension of the Standard Model (MSSM) is in tension with the non-observation of electric dipole moments (EDMs), since the level of CP-violation responsible for electroweak baryogenesis is believed to generate unavoidably large EDMs. We show that CP-violation in the bino-Higgsino sector of the MSSM can account for successful electroweak baryogenesis without inducing large EDMs. This observation weakens the correlation between electroweak baryogenesis and EDMs, and makes the bino-driven electroweak baryogenesis scenario the least constrained by EDM limits. Taking this observation together with the requirement of a strongly first-order electroweak phase transition, we argue that a bino-driven scenario with a light stop is the most phenomenologically viable MSSM electroweak baryogenesis scenario.