Supersymmetric CP-violating currents and electroweak baryogenesis

In this work we compute the CP-violating currents of the right-handed stops and higgsinos, induced by the presence of non-trivial vacuum expectation values of the Higgs fields within the context of the minimal supersymmetric extension of the Standard Model (MSSM) with explicit CP-violating phases. Using the Keldysh formalism, we perform the computation of the currents at finite temperature, in an expansion of derivatives of the Higgs fields, Contrary to previous works, we implement a resummation of the Higgs mass insertion effects to all orders in perturbation theory. White the components of the right-handed stop current j((t) over tildeR)(mu) become proportional to the difference H-2 a(mu) H-1 - H-1 a(mu) H-2 (suppressed by Delta beta), the higgsino currents, j((H) over tildel)(mu), proportional to both H(2)a(mu)H(1) +/- H-1 a(mu)H(2). For large values of the charged Higgs mass and moderate values of tan B the contribution to the source proportional to H(2)a(mu)H(1) + H(1)a(mu)H(2) in the diffusion equations become sizeable, although it is suppressed by the higgsino number violating interaction rate Gamma (-1/2)(mu). For small values of the wall velocity, 0.04 less than or equal to v(omega) less than or equal to 0.1, the total contribution leads to acceptable values of the baryon asymmetry for values of the CP-violating phases phi (CP) in the range 0.04 less than or equal to | sin phi (CP)| less than or equal to 1. Finally, we comment on the relevance of the latest results of Higgs searches at LEP2 for the mechanism of electroweak baryogenesis within the MSSM, (C) 2001 Elsevier Science B.V. All rights reserved.