Search for Z′ resonances decaying to tt-bar in dilepton+jets final states in pp collisions at s√=7 TeV

Abstract

A search for resonances decaying to top quark-antiquark pairs is performed using a dilepton+jets data sample recorded by the CMS experiment at the LHC in pp collisions at s√=7 TeV corresponding to an integrated luminosity of 5.0 fb(−1). No significant deviations from the standard model background are observed. Upper limits are presented for the production cross section times branching fraction of top quark-antiquark resonances for masses from 750 to 3000 GeV. In particular, the existence of a leptophobic topcolor particle Z′ is excluded at the 95% confidence level for resonance masses M(Z′)<1.3 TeV for Γ(Z′)=0.012M(Z′), and M<1.9 TeV for Γ(Z′)=0.10M(Z′).