Speaker: Wen Yin
Title: Baryogenesis via active neutrino oscillation
Host: John Terning
Room: 432
Abstract: Just after the inflation, leptons can be produced from direct decay of the inflaton or scattering. These leptons undergo flavor oscillation which can induce CP-violation, until they are thermalized. 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. It turns out that the CP violation can explain the baryon asymmetry of the Universe. In the case that the leptons are produced by the scattering between the Higgs boson and the thermal plasma, the CP-violation originates from the CP phases in the Pontecorvo-Maki-Nakagawa-Sakata matrix and thus the scenario can be tested by terrestrial experiments. We also discuss an application of the mechanism.
