Search for new gauge bosons decaying into dielectrons inp¯pcollisions at √s=1.8 TeV

We have searched for heavy neutral gauge bosons (${\mathit{Z}}^{\mathcal{’}}$) in p¯p collisions at √s=1.8 TeV. The data were obtained using the CDF detector during the 1992–1993 run corresponding to an integrated luminosity of 19.7±0.7 ${\mathrm{pb}}^{\mathrm{-}1}$. We present a 95% confidence level upper limit on the production cross section times the branching ratio of ${\mathit{Z}}^{\mathcal{’}}$ decaying into dielectrons as a function of ${\mathit{Z}}^{\mathcal{’}}$ mass. Assuming standard model coupling strengths, we exclude a ${\mathit{Z}}^{\mathcal{’}}$ with a mass less than 505 GeV/${\mathit{c}}^2$. We also present lower mass limits for ${\mathit{Z}}^{\mathcal{’}}$ bosons from ${\mathrm{E}}_6$ models and the alternative left-right model.