Year: 1998
Type: article
Abstract: 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 $\mathrm{CP}$-violating phases in the parameters associated with the left-right top squark mixing term and the Higgsino mass \ensuremath{\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. $\mathrm{CP}$-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 $\mathrm{CP}$-violating phase $|\mathrm{sin}{\ensuremath{\varphi}}_{\ensuremath{\mu}}|$ as small as ${10}^{\ensuremath{-}3}$ (or even smaller) is enough to generate the observed baryon asymmetry.
Author: A. Riotto
Institution: European Organization for Nuclear Research
Language: English
Subfield: Nuclear and High Energy Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: bronze
OpenAlex ID: W2042660219