Higgs Bosons in the Simplest SUSY Models.

Nowadays, in the MSSM, the moderate values of tan β are almost excluded by the LEP II lower bound on the mass of the lightest Higgs boson. In the next-to-minimal supersymmetric standard model (NMSSM), the theoretical upper bound on it increases and reaches a maximal value in the limit of strong Yukawa coupling, where all solutions to renormalization-group equations are concentrated near the quasifixed point. For a calculation of the Higgs boson spectrum, the perturbation-theory method can be applied. We investigate the particle spectrum within the modified NMSSM, which leads to the selfconsistent solution in the limit of strong Yukawa coupling. This model allows one to get m[sub h] ∼ 125 GeV at tan β ≥ 1.9. In the model under investigation, the mass of the lightest Higgs boson does not exceed 130.5 ± 3.5 GeV. The upper bound on the mass of the lightest CP-even Higgs boson in more complicated supersymmetric models is also discussed. [ABSTRACT FROM AUTHOR]