Beyond MSSM Baryogenesis

TL;DR

This paper explores how extending the MSSM as an effective low-energy theory with a TeV-scale cutoff broadens the parameter space for electroweak baryogenesis, making it more natural and introducing new CP violation mechanisms.

Contribution

It demonstrates that a low-scale MSSM extension allows for lighter stops, a heavier Higgs, and new CP violation sources, enhancing baryogenesis viability.

Findings

Extended MSSM window for baryogenesis.

Lighter stops and heavier Higgs compatible with bounds.

New CP violation sources at tree level.

Abstract

Taking the MSSM as an effective low-energy theory, with a cut-off scale of a few TeV, can make significant modifications to the predictions concerning the Higgs and stop sectors. We investigate the consequences of such a scenario for electroweak baryogenesis. We find that the window for MSSM baryogenesis is extended and, most important, can be made significantly more natural. Specifically, it is possible to have one stop lighter than the top and the other significantly lighter than TeV simultaneously with the Higgs mass above the LEP bound. In addition, various aspects concerning CP violation are affected. Most notably, it is possible to have dynamical phases in the bubble walls at tree level, providing CP violating sources for Standard Model fermions.