Leptogenesis Via Neutrino Production During Higgs Condensate Relaxation

TL;DR

This paper proposes a novel leptogenesis mechanism during Higgs condensate relaxation, where neutrino production in a time-varying Higgs background generates the universe's matter-antimatter asymmetry, especially effective at low reheat scales.

Contribution

It introduces a new leptogenesis scenario involving neutrino production during Higgs condensate relaxation with exact calculations for Majorana fermions under dynamic conditions.

Findings

Leptogenesis can occur via neutrino production during Higgs condensate relaxation.

The mechanism is most effective with rapid Higgs decay and low reheat scale.

Exact Bogoliubov transformation results for Majorana fermions are provided.

Abstract

During inflation, scalar fields, including the Higgs boson, may acquire a nonzero vacuum expectation value, which must later relax to the equilibrium value during reheating. In the presence of the time-dependent condensate, the vacuum state can evolve into a state with a nonzero particle number. We show that, in the presence of lepton number violation in the neutrino sector, the particle production can explain the observed matter-antimatter asymmetry of the universe. We find that this form of leptogenesis is particularly effective when the Higgs condensate decays rapidly and at low reheat scale. As part of the calculation, we present some exact results for the Bogoliubov transformations for Majorana fermions with a nonzero time-dependent chemical potential, in addition to a time-dependent mass.