Search for New High-Mass Particles Decaying to Lepton Pairs inpp¯Collisions ats=1.96TeV

A search for new particles ($X$) that decay to electron or muon pairs has been performed using approximately $200{\mathrm{pb}}^{-1}$ of $p\overline{p}$ collision data at $\sqrt{s}=1.96\mathrm{TeV}$ collected by the CDF II experiment at the Fermilab Tevatron. Limits on $\sigma (p\overline{p}\to X)BR(X\to \ell \ell )$ are presented as a function of dilepton invariant mass $m_{\ell \ell }>150\mathrm{GeV}/c^2$, for different spin hypotheses (0, 1, or 2). The limits are approximately 25 fb for $m_{\ell \ell }>600\mathrm{GeV}/c^2$. Lower mass bounds for $X$ from representative models beyond the standard model including heavy neutral gauge bosons are presented.