Renormalization-group-improved Higgs sector of the minimal supersymmetric model

In the minimal supersymmetric model all Higgs self-coupling parameters are related to gauge couplings at the tree level. Leading-logarithmic radiative corrections to these quantities can be summed using renormalization-group techniques. By this procedure we obtain complete leading-logarithmic radiative corrections to the Higgs boson masses, the $\mathrm{CP}$-even Higgs boson mixing angle, and trilinear Higgs boson couplings. Additional corrections due to squark mixing can be explicitly incorporated into this formalism. These results incorporate nearly all potentially large corrections. Mass shifts to the neutral $\mathrm{CP}$-even Higgs bosons grow with the fourth power of the top-quark mass and can be significant. The phenomenological consequences of these results are examined.