NEGATIVE DELTA-ALPHA WITH 4 FAMILIES IN THE STANDARD MODEL

The possible consequences of heavy, fourth generation fermion, ''vecto r-meson'' bound states, formed by the exchange of the Higgs boson, are discussed. In particular, it is suggested that such bound states coul d make negative contributions to the p parameter, thereby loosening th e perturbative constraint upon the mass of the top quark and/or the ma sses, mass splittings, and other characteristics of a potential fourth generation of heavy fermions. Phenomenological implications such as ' 'monojet'' events, coming from the decay of a heavy neutral lepton in Z --> Nnu(tau)BAR + Nnu(tau)BAR as well as their correlations to the f lavor-changing decay Z --> bsBAR + bsBAR are also discussed. The analy sis also extends to the standard model with two Higgs doublets.