Leptogenesis via Neutrino Oscillation Magic

TL;DR

This paper proposes a novel leptogenesis mechanism where flavor oscillations of leptons after inflation, influenced by CP violation in neutrino mixing, can explain the Universe's baryon asymmetry, linking cosmology with neutrino physics.

Contribution

It introduces a new leptogenesis scenario based on neutrino flavor oscillations and CP violation, connecting early Universe dynamics with low-energy neutrino experiments.

Findings

CP violation in flavor oscillation can generate baryon asymmetry

The scenario links leptogenesis to measurable neutrino CP phases

Reheating via inflaton decay influences baryon asymmetry production

Abstract

The possibility of generating the baryon asymmetry of the Universe via flavor oscillation in the early Universe is discussed. After the inflation, leptons are born in some states, travel in the medium, and are eventually projected onto flavor eigenstates due to the scattering via the Yukawa interactions. By using the Lagrangian of the Standard Model with the Majorana neutrino mass terms, llHH, we follow the time evolution of the density matrices of the leptons in this very first stage of the Universe and show that the CP violation in the flavor oscillation can explain the baryon asymmetry of the Universe. In the scenario where the reheating is caused by the decay of the inflaton into the Higgs bosons, the baryon asymmetry is generated by the CP phases in the Pontecorvo-Maki-Nakagawa-Sakata matrix and thus can be tested by the low energy neutrino experiments.