Electroweak baryogenesis window in non standard cosmologies

TL;DR

This paper explores how nonstandard cosmological models can relax the constraints on electroweak baryogenesis, allowing for a broader parameter space compatible with Higgs mass bounds and baryon asymmetry preservation.

Contribution

It demonstrates that nonstandard cosmologies, such as matter-dominated or braneworld scenarios, can extend the electroweak baryogenesis window beyond standard cosmology constraints.

Findings

Nonstandard cosmologies weaken Higgs mass bounds.

Baryon asymmetry preservation is feasible in modified expansion histories.

Explicit models include matter-dominated and braneworld scenarios.

Abstract

In this work we show that the new bounds on the Higgs mass are more than difficult to reconcile with the strong constraints on the physical parameters of the Standard Model and the Minimal Supersymmetric Standard Model imposed by the preservation of the baryon asymmetry. This bound can be weakened by assuming a nonstandard cosmology at the time of the electroweak phase transition, reverting back to standard cosmology by BBN time. Two explicit examples are an early period of matter dominated expansion due to a heavy right handed neutrino (see-saw scale), or a nonstandard braneworld expansion.