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 of the Higgs bosons in the minimal supersymmetric standard model (MSSM) augmented by a single gauge singlet, the so-called next-to-minimal supersymmetric standard model (NMSSM). Our method is based on the one-loop effective potential and includes effects of top quark, squark, Higgs boson, and Higgsino loops. We discuss the renormalization group flows of Yukawa couplings and the upper bound on the lightest {ital CP}-even neutral 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 phenomenology including radiative corrections. We survey as much of the parameter space of the Higgs sector of the NMSSM as is practical, and analyze the full spectrum of Higgs boson masses and couplings in these regions of parameter space. Characteristic signatures of the NMSSM such as light charged bosons and weakly coupled neutral scalars are discussed, as are the relative sizes of the various radiative corrections. The MSSM is also discussed as a limiting case of the NMSSM for comparison.