Search for Excited and Exotic Electrons in the e-gamma Decay Channel in p-pbar Collisions at sqrt(s) = 1.96 TeV

TL;DR

This study searches for excited and exotic electrons decaying into an electron and a photon in proton-antiproton collisions at 1.96 TeV, setting new exclusion limits on their masses in different theoretical models.

Contribution

First search for excited and exotic electrons in the e-gamma channel at Tevatron, establishing new mass exclusion limits in contact interaction and gauge-mediated models.

Findings

No excess signal observed above Standard Model background.

Excluded excited electron masses between 132 and 879 GeV/c^2 in contact interaction model.

Excluded excited electron masses between 126 and 430 GeV/c^2 in gauge-mediated model.

Abstract

We present a search for excited and exotic electrons (e*) decaying to an electron and a photon, both with high transverse momentum. We use 202/pb of data collected in p-pbar collisions at sqrt(s) = 1.96 TeV with the CDF II detector. No signal above Standard Model expectation is seen for associated ee* production. We discuss the e* sensitivity in the parameter space of the excited electron mass M(e*) and the compositeness energy scale Lambda. In the contact interaction model, we exclude 132 < M(e*) < 879 GeV/c^2 for Lambda = M(e*) at 95% confidence level (C.L.). In the gauge-mediated model, we exclude 126 < M(e*) < 430 GeV/c^2 at 95% C.L. for the phenomenological coupling f/Lambda ~ 0.01/GeV.