The closed time- path formalism is a powerful Green's function formulation to describe non- equilibrium phenomena in field theory and it leads to a complete non- equilibrium quantum kinetic theory. We make use of this formalism to write down the set of quantum Boltzmann equations relevant for leptogenesis. They manifest memory effects and off-shell corrections. In particular, memory effects lead to a time- dependent CP asymmetry whose value at a given instant of time depends upon the previous history of the system. This result is particularly relevant when the asymmetry is generated by the decays of nearly mass- degenerate heavy states, as in resonant or soft leptogenesis.
|Titolo:||Quantum Boltzmann equations and leptogenesis|
|Autori:||De Simone A; Riotto A|
|Rivista:||JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS|
|Data di pubblicazione:||2007|
|Digital Object Identifier (DOI):||10.1088/1475-7516/2007/08/002|
|Appare nelle tipologie:||1.1 Journal article|