We study radiative electroweak symmetry breaking in the minimal supersymmetric standard model (MSSM). We employ the two-loop renormalization group equations for running masses and couplings taking into account sparticle threshold effects. The decoupling of each particle below its threshold is realized by a step function in all one-loop renormalization group equations. This program requires the calculation of all wave function, vertex, and mass renormalizations for all particles involved. Adapting our numerical routines to take care of the succesive decoupling of each particle below its threshold, we compute the mass spectrum of sparticles and Higgs bosons consistent with the existing experimental constraints. The effect of the threshold corrections is in general of the same order of magnitude as the two-loop contributions with the exception of the heavy Higgs bosons and those neutralino and chargino states that are nearly Higgsinos for large values of the parameter μ. © 1996 The American Physical Society.

• Received 2 August 1995

DOI:https://doi.org/10.1103/PhysRevD.53.3793