Search for pair-produced heavy quarks decaying to Wq in the two-lepton channel at sqrt(s) = 7 TeV with the ATLAS detector

TL;DR

This paper reports a search for heavy quark pairs decaying to Wq in dilepton final states at 7 TeV, setting mass exclusion limits up to 350 GeV based on ATLAS data.

Contribution

First search for heavy-quark pair production decaying to Wq in dilepton channels at 7 TeV with ATLAS, establishing new mass exclusion limits.

Findings

No excess observed over Standard Model predictions.

Heavy quarks with mass less than 350 GeV are excluded at 95% CL.

Method for reconstructing heavy quark candidates in dilepton events.

Abstract

A search is presented for heavy-quark pair production (QQbar) under the decay hypothesis QQbar to WqWq with q = u,d,c,s,b. The search is performed with 1.04 fb^-1 of integrated luminosity from pp collisions at sqrt(s) = 7 TeV collected by the ATLAS detector at the CERN LHC. Dilepton final states are selected, requiring large missing transverse momentum and at least two jets. Mass reconstruction of heavy quark candidates is performed by assuming that the W boson decay products are nearly collinear. The data are in agreement with Standard Model expectations; a heavy quark with mass less than 350 GeV is excluded at 95% confidence level.