Fermion Back-Reaction and the Sphaleron

TL;DR

This paper introduces a new sphaleron solution accounting for finite fermionic density effects, showing that increased fermion density lowers the energy barrier and potentially enhances transition rates, with implications for baryogenesis.

Contribution

A novel sphaleron solution incorporating fermionic density effects, providing insights into transition rates in high-density environments.

Findings

Sphaleron energy decreases with increasing fermionic density

Transition rates may increase due to lowered energy barriers

Standard baryogenesis predictions remain largely unaffected

Abstract

Using a simple model, a new sphaleron solution which incorporates finite fermionic density effects is obtained. The main result is that the height of the potential barrier (sphaleron energy) decreases as the fermion density increases. This suggests that the rate of sphaleron-induced transitions increases when the fermionic density increases. However the rate increase is not expected to change significantly the predictions from the standard sphaleron-induced baryogenesis scenarios.