The electroweak phase transition (EWPT) in the secluded-U(1)′-extended MSSM (sMSSM) is studied. Using the effective potential at zero and finite temperatures, we search for the non-MSSM-like EWPT in which the light stop mass is larger than the top quark mass. Scanning the parameters relevant to the EWPT, the upper limits of the Higgs boson masses, which are consistent with the strong first order EWPT, are derived. For the lightest CP-even and -odd Higgs bosons, we find mH1 <~160text GeV {m_{{H_1}}} lesssim 160{text{ GeV}} and mA1 <~250text GeV {m_{{A_1}}} lesssim 250{text{ GeV}} , respectively. In the sMSSM, the tree-level CP violation is possible by the complex soft supersymmetry breaking masses. It is observed that such a CP-violating effect does not spoil the strong first order EWPT for the typical parameter sets.
展开▼
