Search for Heavy Particles Decaying into Electron-Positron Pairs inpp¯Collisions

We present results of searches for technirho $\left({\rho }_T\right)$, techniomega $\left({\omega }_T\right)$, and $Z^{\prime }$ particles, using the decay channels ${\rho }_T,{\omega }_T{,Z}^{\prime }\to e^{+}{e}^{-}$. The search is based on $124.8{\mathrm{pb}}^{-1\mathrm{}}$ of data collected by the D0 detector at the Fermilab Tevatron during 1992–1996. In the absence of a signal, we set $95\%$ C.L. upper limits on the cross sections for the processes $p\overline{p}\to {\rho }_T,{\omega }_T,Z^{\prime }\to e^{+}{e}^{-}$ as a function of the mass of the decaying particle. For certain model parameters, we exclude the existence of degenerate ${\rho }_T$ and ${\omega }_T$ states with masses below about 200 GeV. We exclude a $Z^{\prime }$ with mass below 670 GeV, assuming that it has the same couplings to fermions as the $Z$ boson.