Upper mass bounds for the light neutral higgs boson in N=1 supergravity theories

A new evaluation of absolute upper mass bounds for the light neutral Higgs boson in N=1 supergravity theories with a minimal low energy particle content is presented for a top quark mass in the range 30 GeV⩽ m_t⩽50 GeV. The bounds are found to significantly exceed previous estimated values. The effects due to some noncanonical versions of the model are shown to be rather unimportant. A finite gaugino mass, however, lowers the bounds significantly.