Leptogenesis via preheating

TL;DR

This paper explores how non-perturbative fermion production during preheating can generate the right-handed neutrinos needed for leptogenesis, providing a viable mechanism for explaining the universe's baryon asymmetry.

Contribution

It demonstrates that non-perturbative fermion production in an expanding universe can efficiently produce super-heavy neutrinos for leptogenesis.

Findings

Non-perturbative production is effective up to 10^17-10^18 GeV.

This mechanism can successfully generate the baryon asymmetry.

Fermion production surpasses perturbative methods in efficiency.

Abstract

Leptogenesis constitues a very simple scenario to achieve the baryon asymmetry that we observe today. It requires only the presence of right handed neutrinos (which arise very naturally in many extensions of the Standard Model) and depends crucially on the mechanism responsible for their production. In particular, when their mass exceeds the inflaton mass (10^13 GeV in chaotic inflation) only non perturbative production can occur. It is shown here that non perturbative production of fermions in an expanding Universe is a very efficient mechanism up to masses of order of (10^17 - 10^18) GeV, and that it can be easily applied to solve the baryon asymmetry problem.