More relaxed supersymmetric electroweak baryogenesis

We reanalyze the issue of the generation of baryon asymmetry at the electroweak phase transition in the MSSM and compute the baryon asymmetry assuming the presence of nontrivial CP-violating phases in the parameters associated with the left-right top squark mixing term and the Higgsino mass mu. Making use of the closed time-path formalism of nonequilibrium field theory, we write down a set of quantum Boltzmann equations describing the local number density asymmetries of the particles involved in supersymmetric electroweak baryogenesis. CP-violating sources manifest "memory" effects which are typical of the quantum transport theory and are not present in the classical approach. Compared to previous estimates, these non-Markovian features enhance the final baryon asymmetry by at least two orders of magnitude. This means that a CP-violating phase \sin phi(mu)\ as small as 10(-3) (or even smaller) is enough to generate the observed baryon asymmetry. [S0556-2821(98)08221-6]