Non-equilibrium electroweak baryogenesis from preheating after inflation

TL;DR

This paper proposes a new electroweak baryogenesis scenario occurring during preheating after inflation, where Higgs field dynamics induce baryon asymmetry without wash-out, supported by numerical simulations.

Contribution

It introduces a novel baryogenesis mechanism at the electroweak scale triggered by preheating, with theoretical estimates and supporting (1+1)D simulations.

Findings

Large sphaleron transition rates during preheating.

Baryon asymmetry generated below 100 GeV.

Numerical simulations confirm theoretical predictions.

Abstract

We present a novel scenario for baryogenesis in a hybrid inflation model at the electroweak scale, in which the Standard Model Higgs field triggers the end of inflation. One of the conditions for successful baryogenesis, the departure from thermal equilibrium, is naturally achieved at the stage of preheating after inflation. The inflaton oscillations induce large occupation numbers for long-wavelength configurations of Higgs and gauge fields, which leads to a large rate of sphaleron transitions. We estimate this rate during the first stages of reheating and evaluate the amount of baryons produced due to a particular type of higher dimensional CP violating operator. The universe thermalizes through fermion interactions, at a temperature below critical, $T_{rh} < 100$ GeV, preventing the wash-out of the produced baryon asymmetry. Numerical simulations in (1+1) dimensions support our theoretical analysis.