INCLUSION OF $Z \to b\bar{b}$ VERTEX CORRECTIONS IN PRECISION ELECTROWEAK TESTS ON THE Sp(6)L× U(1)Y MODEL

Abstract

We extend our previous work on the precision electroweak tests in the Sp (6)L× U (1)Y family model to include for the first time the important [Formula: see text] vertex corrections encoded in a new variable ∊b, utilizing all the latest LEP data. We include in our analysis the one-loop EW radiative corrections due to the new bosons in terms of ∊1,b and ΔΓZ. We find that the correlation between ∊1 and ∊b makes the combined constraint much stronger than the individual ones. The model is consistent with the recent CDF result of [Formula: see text] but it; cannot accommodate mt≳195 GeV .