Search for High-Mass \boldmath$e^+e^-$ Resonances in \boldmath$p\bar{p}$ Collisions at \boldmath$\sqrt{s}=$1.96 TeV

TL;DR

This paper reports a search for high-mass electron-positron resonances in proton-antiproton collisions at 1.96 TeV, finding a slight excess at 240 GeV and setting exclusion limits on certain new physics models.

Contribution

First search for high-mass $e^+e^-$ resonances at Tevatron, providing new limits on $Z'$ and Randall-Sundrum graviton masses.

Findings

Observed a 2.5 sigma excess at 240 GeV/$c^2$

Excluded $Z'$ masses below 963 GeV/$c^2$

Excluded Randall-Sundrum graviton masses below 848 GeV/$c^2$

Abstract

A search for high-mass resonances in the $e^+e^-$ final state is presented based on 2.5 fb$^{-1}$ of $\sqrt{s}=$1.96 TeV $p\bar{p}$ collision data from the CDF II detector at the Fermilab Tevatron. The largest excess over the standard model prediction is at an $e^+e^-$ invariant mass of 240 GeV/$c^2$. The probability of observing such an excess arising from fluctuations in the standard model anywhere in the mass range of 150--1,000 GeV/$c^2$ is 0.6% (equivalent to 2.5 $\sigma$). We exclude the standard model coupling $Z'$ and the Randall-Sundrum graviton for $k/\overline{M}_{Pl}=0.1$ with masses below 963 and 848 GeV/$c^2$ at the 95% credibility level, respectively.