Search for Heavy Top-like Quarks tprime->Wq Using Lepton Plus Jets Events in 1.96 TeV p-pbar Collisions

TL;DR

This paper reports a search for a hypothetical heavy top-like quark, tprime, in proton-antiproton collisions, finding no evidence but setting a lower mass limit of 311 GeV/c2 at 95% confidence level.

Contribution

First search for tprime quarks decaying to Wq in proton-antiproton collisions, establishing mass limits using the CDF II detector data.

Findings

No evidence for tprime production.

Lower mass limit of 311 GeV/c2 at 95% CL.

Constraints on tprime production cross section.

Abstract

We present the results of a search for a new heavy top-like quark, tprime, decaying to a W boson and another quark using the CDF II Detector in Run II of the Tevatron ppbar collider. New top-like quarks are predicted in a number of models of new physics. Using a data sample corresponding to 2.8 fb-1 of integrated luminosity we fit the observed spectrum of total transverse energy and reconstructed quark mass to a combination of background plus signal. We see no evidence for tprime production, so use this result to set limits on the tprime tprimebar production cross section times the branching ratio of tprime to Wq and infer a lower limit of 311 GeV/c2 on the mass of the tprime at 95% CL.