Speaker
Description
In order to describe low-scale leptogenesis in the early Universe, we calculate in a beyond SM settings the measure of CP violation, which comes from the interference of a tree-level and one-loop decay amplitudes. The imaginary part of the one-loop vertex function is written using both finite temperature cutting rules of the real time formalism and analytic continuation in the imaginary time formalism. The CP violation parameter is calculated numerically for non-vanishing masses using the contribution of all the cuts of the vertex function. The result is compared quantitatively to earlier calculations and used to determine through Boltzmann equations the lepton number created in the superweak extension of the SM (SWSM, a gauge U(1) extension of SM, containing an extra scalar and right-handed neutrinos).
