Search for tb Resonances in Proton-Proton Collisions at sqrt[s]=7  TeV with the ATLAS Detector

This Letter presents a search for tb resonances in 1:04 fb1 of LHC proton-proton collision data collected by the ATLAS detector at a center-of-mass energy of 7 TeV. Events with a lepton, missing transverse momentum, and two jets are selected and the invariant mass of the corresponding final state is reconstructed. The search exploits the shape of the tb invariant mass distribution compared to the expected standard model backgrounds. The model of a right-handed W0R with standard model-like couplings is chosen as the benchmark model for this search. No statistically significant excess of events is observed in the data, and upper limits on the cross section times the branching ratio of W0R resonances at 95% C.L. lie in the range of 6.1–1.0 pb for W0R masses ranging from 0.5 to 2.0 TeV. These limits are translated into a lower bound on the allowed right-handed W0R mass, giving mW0R > 1:13 TeV at 95% C.L.