PUB - Publikationen an der Universität Bielefeld

In this paper we embed the light stop scenario, a MSSM framework whichexplains the baryon asymmetry of the universe through a strong first orderelectroweak phase transition, in a top-down approach. The required low energyspectrum consists in the light SM-like Higgs, the right-handed stop, thegauginos and the Higgsinos while the remaining scalars are heavy. This spectrumis naturally driven by renormalization group evolution starting from a heavyscalar spectrum at high energies. The latter is obtained through asupersymmetry-breaking mix of gauge mediation, which provides the scalarsmasses by new gauge interactions, and gravity mediation, which generatesgaugino and Higgsino masses. This supersymmetry breaking also explains the \mu\and B_\mu\ parameters necessary for electroweak breaking and predicts smalltri-linear mixing terms A_t in agreement with electroweak baryogenesisrequirements. The minimal embedding predicts a Higgs mass around itsexperimental lower bound and by a small extension higher masses m_H\lesssim 127GeV can be accommodated.