Yukawa and triscalar processes in electroweak baryogenesis
We derive the contributions to the quantum transport equations for electroweak baryogenesis due to decays and inverse decays induced by triscalar and Yukawa interactions. In the minimal supersymmetric standard model (MSSM), these contributions give rise to couplings between Higgs and fermion supermultiplet densities, thereby communicating the effects of CP-violation in the Higgs sector to the baryon sector. We show that the decay and inverse decay-induced contributions that arise at zeroth order in the strong coupling, alphas, can be substantially larger than the [script O](alphas) terms that are generated by scattering processes and that are usually assumed to dominate. We revisit the often-used approximation of fast Yukawa-induced processes and show that for realistic parameter choices it is not justified. We solve the resulting quantum transport equations numerically with special attention to the impact of Yukawa rates and study the dependence of the baryon-to-entropy ratio YB on MSSM parameters.
Additional Information© 2006 The American Physical Society (Received 30 March 2006; published 21 June 2006) We wish to thank C. Wagner, M. Carena, and M. Wise for useful discussions, and A. Pilaftsis for pointing us to the work in  on two-loop SUSY contributions to EDMs. C.L. is grateful to the high energy and nuclear theory groups at Caltech for their hospitality during portions of this work. The work of M.J.R.M. and S.T. was supported by U.S. Department of Energy Contract No. DE-FG02-05ER41361 and by a National Science Foundation Grant No. PHY00-71856. V.C. was supported by Caltech through the Sherman Fairchild fund. The work of C.L. was supported by the U.S. Department of Energy Contract No. DE-FG02-00ER41132.
Published - CIRprd06a.pdf