CALCULABLE UPPER LIMIT ON THE MASS OF THE LIGHTEST HIGGS BOSON IN PERTURBATIVELY VALID SUPERSYMMETRIC THEORIES WITH ARBITRARY HIGGS SECTORS

We derive a calculable upper limit on the mass of the lightest Higgs b oson in perturbatively valid supersymmetric theories with arbitrary Hi ggs sectors. We assume a supersymmetry spectrum around or below 1 TeV and the standard model gauge symmetry, but place no restrictions on th e Higgs sector. We estimate m(h)0 < 146 GeV for M(t) greater than or s imilar to 100 GeV from all effects except possible additional heavy fe rmions beyond top (which could increase the limit approximately 12 GeV per extra family); for 60 less than or similar to M(t) less than or s imilar to 100 GeV we find m(h)0 < 156 GeV. In most explicitly construc ted models the lightest Higgs boson mass does not saturate the upper l imit.