INDICATIONS FROM PRECISION ELECTROWEAK PHYSICS CONFRONT THEORETICAL BOUNDS ON THE MASS OF THE HIGGS-BOSON

An updated fit to the precision electroweak data and to the direct mea surement of the top quark mass m(t) provides significant constraints o n m(t) and on the Higgs boson mass M(H): m(t)/GeV = 172 +/- 6 and log( 10)(M(H)/GeV) = 2.16 +/- 0.33, with an error correlation rho = 0.5. We integrate the (M(H), m(t)) probability distribution found in this ana lysis over various zones of the (M(H), m(t)) plane defined by one-side d experimental and theoretical bounds on the Higgs boson mass, both in the Standard Model and in its minimal supersymmetric extension. The c omparison of the cumulative probabilities gives interesting informatio n on the likelihood that the true value of M(H) is compatible with dif ferent theoretical scenarios.