Renormalization-group analysis of the Higgs sector in the minimal supersymmetric standard model

Abstract

We examine the particle spectra of the Higgs sector in the minimal supersymmetric extension of the standard model using the one-loop renormalization group evolution of the scalar self-couplings. We treat the general case in which there are two light Higgs doublets below the soft supersymmetry breaking scale M SUSY. The model with only one light CP-even neutral scalar particle appears as a particular limiting case in our analysis. Using theoretical and experimental results, we obtain upper and lower bounds on the neutral CP-even and charged Higgs mass spectrum. The triviality bounds on the top and Higgs masses are also analyzed, yielding constraints on the range of mass parameters consistent with possible grand unification scenarios. We obtain that for an effective cutoff scale Λ ⋍ 10 16 GeV (10 10 Gev) , a soft supersymmetry breaking scale M SUSY ⋍ 1 TeV and a CP-odd state mass m A ⋍ 40 GeV , the lightest CP-even state mass is bounded to be m h ⩽ 52 GeV (60 GeV). In addition, for the same values of Λ and M SUSY, and for m A ⩾ M Z, the tree-level relation m h ⩽ m A is fulfilled. Our analysis indicates that, in the simplest grand unification scenarios with M GUT ⋍ 10 16 GeV and M SUSY ⋍ 1 TeV , the decay mode h → AA is only allowed if m A ⩽ 26 GeV.