Leptogenesis with Dirac Neutrinos

TL;DR

This paper proposes a leptogenesis mechanism involving Dirac neutrinos and sphaleron processes that can generate the Universe's baryon asymmetry without initial B or L violation, consistent with current neutrino mass data.

Contribution

It introduces a novel neutrinogenesis mechanism with Dirac neutrinos that explains baryon asymmetry, supported by a simple toy model.

Findings

Neutrino mass constraints are compatible with current experimental data.

The mechanism can produce the observed baryon asymmetry.

Sphaleron processes can generate baryon asymmetry with Dirac neutrinos.

Abstract

We describe a "neutrinogenesis" mechanism whereby, in the presence of right-handed neutrinos with sufficiently small pure Dirac masses, (B+L)-violating sphaleron processes create the baryon asymmetry of the Universe, even when B=L=0 initially. It is shown that the resulting neutrino mass constraints are easily fulfilled by the neutrino masses suggested by current experiments. We present a simple toy model which uses this mechanism to produce the observed baryon asymmetry of the Universe. (PostScript Errors corrected in latest Version).