Search for New Neutral Bosons at Future Colliders

Abstract

This is a short review of present and future limits on new neutral gauge bosons, in particular on hadrophilic or leptophobic $Z^{\prime }$s recently proposed to interpret the observed fluctuations of $\hat{I}{“}_{c,b}$ at LEP. Light gauge bosons coupled to lepton number differences or to baryon number are also examples of the model dependence of these bounds. The mixing between the $U(1)$ factors plays an important role in the phenomenology of these extended electroweak models. Future improvements based on the analysis of precise electroweak data are emphasized.

7 pages, no figures. Full Postscript file available at: http://deneb.ugr.es/preprints/ugft55.ps.gz Three references added