CP violation Beyond the MSSM: Baryogenesis and Electric Dipole Moments

TL;DR

This paper explores how non-renormalizable operators in the MSSM Higgs sector can enable electroweak baryogenesis and affect electric dipole moments, revealing new CP-violating mechanisms and relaxing previous constraints.

Contribution

It introduces leading-order non-renormalizable operators in the MSSM Higgs sector, demonstrating their impact on baryogenesis and electric dipole moments, and showing expanded viable parameter space.

Findings

Spontaneous baryogenesis driven by Higgs phase change is possible.

Top and stop CP-violating sources can be effective.

Baryogenesis viability is increased, reducing fine-tuning issues.

Abstract

We study electroweak baryogenesis and electric dipole moments in the presence of the two leading-order, non-renormalizable operators in the Higgs sector of the MSSM. Significant qualitative and quantitative differences from MSSM baryogenesis arise due to the presence of new CP-violating phases and to the relaxation of constraints on the supersymmetric spectrum (in particular, both stops can be light). We find: (1) spontaneous baryogenesis, driven by a change in the phase of the Higgs vevs across the bubble wall, becomes possible; (2) the top and stop CP-violating sources can become effective; (3) baryogenesis is viable in larger parts of parameter space, alleviating the well-known fine-tuning associated with MSSM baryogenesis. Nevertheless, electric dipole moments should be measured if experimental sensitivities are improved by about one order of magnitude.