CP asymmetry in heavy Majorana neutrino decays at finite temperature

by Simone Biondini (TUM Munich)

Tuesday Dec 15, 2015, 12:00 PM → 1:00 PM Europe/Madrid

IFAE Seminar room (IFAE)

In a model where Majorana neutrinos heavier than the electroweak scale couple to Standard Model Higgs bosons and leptons, we compute systematically thermal corrections to the direct and indirect CP asymmetries in the Majorana neutrino decays. These are key ingredients entering the equations that describe the thermodynamic evolution of the induced lepton-number asymmetry eventually leading to the baryon asymmetry in the universe. We compute the thermal corrections in an effective field theory framework that assumes the temperature smaller than the masses of the Majorana neutrinos and larger than the electroweak scale. We provide the leading corrections in an expansion of the temperature over the mass, together with the analysis of sub-leading corrections induced by some higher order operators. Different arrangements for the heavy neutrinos mass spectrum are considered.