AZ′with enhanced couplings to quarks: A bridge from CERN LEP 1, SLC, and CDF to LEP 2 anomalies

In order to explain possible departures from the standard model (SM) predictions for $b\overline{b}$ and $c\overline{c}$ production at the $Z$ peak, we propose the existence of a $Z^{\prime }$ vector boson with enhanced couplings to quarks. We first show that this proposal is perfectly consistent with the full set of LEP 1 and SLC results. In particular, $Z-Z^{\prime }$ mixing effects naturally explain the fact that ${\Gamma }_b$ and ${\Gamma }_c$ deviate from the SM in opposite directions. We then show that there is a predicted range for enhanced $Z^{\prime }q\overline{q}$ couplings which explains, for a precise and interesting range of $Z^{\prime }$ masses, the excess of dijet events seen at CDF. A $Z^{\prime }$ with such couplings and mass would produce clean observable effects in $b\overline{b}$ and in total hadronic production at LEP 2.