Search for single b^⁎-quark production with the ATLAS detector at √s=7 TeV

The results of a search for an excited bottom-quark b^⁎ in pp collisions at s=7 TeV, using 4.7 fb⁻¹ of data collected by the ATLAS detector at the LHC are presented. In the model studied, a single b^⁎-quark is produced through a chromomagnetic interaction and subsequently decays to a W boson and a top quark. The search is performed in the dilepton and lepton + jets final states, which are combined to set limits on b^⁎-quark couplings for a range of b^⁎-quark masses. For a benchmark with unit size chromomagnetic and Standard Model-like electroweak b^⁎ couplings, b^⁎ quarks with masses less than 870 GeV are excluded at the 95% credibility level.