Can the mass of the lightest Higgs boson of the minimal supersymmetric model be larger thanmZ?
In the minimal supersymmetric model (MSSM), the tree-level mass of the lightest Higgs scalar ${\mathit{h}}^{0}$ cannot be larger than the mass of the Z boson. We have computed the one-loop radiative correction to the upper bound on ${\mathit{m}}_{\mathit{h}}^{0}$ as a function of the free parameters of the MSSM. We find that the dominant correction to ${\mathit{m}}_{\mathit{h}}^{0}$-${\mathit{m}}_{\mathit{Z}}$ is large and positive and grows like ${\mathit{m}}_{\mathit{t}}^{4}$, where ${\mathit{m}}_{\mathit{t}}$ is the top-quark mass. As a result, the MSSM cannot be ruled out if the CERN ${\mathit{e}}^{+}$${\mathit{e}}^{\mathrm{\ensuremath{-}}}$ collider LEP-200 fails to discover the Higgs boson.