We discuss present neutral current data constraints (combined with MW and MZ measurements) on mt (and mH) in the minimal gauge extension of the standard model. The extra gauge boson mass MZ, is the only new parameter (for fixed new gauge couplings λ and θ1). Fits performed with MZ, and mt free, translate into allowed regions in the MZ,-mt plane where the MZ, lower bound is correlated with the mt upper bound. As a consequence, the mt upper bound in extended electroweak models is stronger (lower) than the one obtained in the minimal standard model, and coincides with it in the limits MZ, → ∞. The influence of the different pieces of data on the fits is also discussed. We briefly comment on other constraints, such as those from charged current data and direct production at large hadron colliders. © 1991.
|Journal||Nuclear Physics, Section B|
|Publication status||Published - 26 Aug 1991|