RADIATIVE-CORRECTIONS TO HIGGS-BOSON MASSES IN THE NEXT-TO-MINIMAL SUPERSYMMETRIC STANDARD MODEL

We perform a systematic study of radiative corrections to the masses o f the Higgs bosons in the minimal supersymmetric standard model (MSSM) augmented by a single gauge singlet, the so-called next-to-minimal su persymmetric standard model (NMSSM). Our method is based on the one-lo op effective potential and includes effects of top quark, squark, Higg s boson, and Higgsino loops. We discuss the renormalization group flow s of Yukawa couplings and the upper bound on the lightest CP-even neut ral Higgs boson mass as a function of the heavier top squark mass and top quark mass. We then give a general discussion of Higgs boson pheno menology including radiative corrections. We survey as much of the par ameter space of the Higgs sector of the NMSSM as is practical, and ana lyze the full spectrum of Higgs boson masses and couplings in these re gions of parameter space. Characteristic signatures of the NMSSM such as light charged bosons and weakly coupled neutral scalars are discuss ed, as are the relative sizes of the various radiative corrections. Th e MSSM is also discussed as a limiting case of the NMSSM for compariso n.