Screening of large exotic scales in the light Higgs mass bound for a general class of supersymmetric models

We consider the class of supersymmetric models whose Higgs sector contains a 'conventional' couple of SU(2)L doublets and an arbitrary number of extra 'exotic' SU(2)LxU(1)y neutral Higgs (possibly related to an extra symmetry group G), with a priori arbitrarily large vevs. 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 mass from the large vevs effects at tree level. At one loop, we show that, if the fermion-sfermion sector is considered, the analogous property 'screens' the lightest Higgs mass under very general assumptions for the symmetry breaking mechanism. (orig.)