SCREENING OF LARGE EXOTIC SCALES IN THE LIGHT HIGGS-BOSON MASS BOUND FOR A GENERAL-CLASS OF SUPERSYMMETRIC MODELS

We consider the class of supersymmetric models whose Higgs sector contains a ''conventional'' pair of SU(2)L doublets and an arbitrary number of extra ''exotic'' SU(2)L X U(1)Y neutral Higgs singlets (possibly related to an extra symmetry group G), with a priori arbitrarily large vacuum expectation values (VEV's). We show that, as a consequence of the functional structure of the scalar potential (dictated by gauge and supersymmetry invariance), a general property exists in the scalar mass matrix which decouples the lightest Higgs-boson mass from the large VEV effects at the tree level. At one loop, we show that, if the fermion-sfermion sector is considered, the analogous property ''screens'' the lightest Higgs-boson mass under very general assumptions for the symmetry-breaking mechanism.