BRST QUANTIZATION OF SU(2 1) ELECTROWEAK THEORY IN THE SUPERCONNECTION APPROACH, AND THE HIGGS MESON MASS/

A superconnection, in which a scalar field enters as a zero-form in th e odd part of the superalgebra, is used in the BRST quantization of th e SU(2/1) ''internally superunified'' electroweak theory. A quantum ac tion is obtained, by applying symmetric BRST/anti-BRST invariance. Eva luating the mass of the Higgs field, we exhibit the consistency betwee n two approaches: (a) applying the supergroup's (gauge) value for lamb da, the coupling of the scalar field's quartic potential, to the conve ntional (spontaneous symmetry breakdown) evaluation; (b) dealing with the superconnection components as a supermultiplet of an (global) inte rnal supersymmetry This result thus provides a general foundation for the use of ''internal'' supergauges. With SU(2/1) broken by the negati ve squared mass term for the Higgs field and with the matter supermult iplets involving added ''effective'' ghost states, there is no reason to expect the symmetry's couplings not to be renormalized. This explai ns the small difference between predicted and measured values for sin( 2) theta(w), namely the other coupling fixed by SU(2/1) beyond the Sta ndard Model's SU(2) x U(1), and where the experimental results are ver y precise. Using the renormalization group equations and those experim ental data, we thus evaluate the energy E(s) at which the SU(2/1) pred icted value of 0.25 is expected to correspond to the experimental valu es. With SU(2/1) precise at that energy E(s) = 5 TeV, we then apply th e renormalization group equations again, this time to evaluate the cor rections to the above lambda, the quartic coupling of the scalar field s; as a result we obtain corrections to the prediction for the Higgs m eson's mass. Our result predicts the Higgs' mass [170 GeV, according t o unrenormalized SU(2/1)] to be as low as 130 +/- 6 GeV, using for the top quark mass the recently measured value of 174 GeV.