Search for resonances in the dilepton mass distribution in pp collisions at √s = 7 TeV

Abstract

A search for narrow resonances at high mass in the dimuon and dielectron channels has been performed by the CMS experiment at the CERN LHC, using pp collision data recorded at √s=7 TeV. The event samples correspond to integrated luminosities of 40 pb^-1 in the dimuon channel and 35 pb^-1 in the dielectron channel. Heavy dilepton resonances are predicted in theoretical models with extra gauge bosons (Z') or as Kaluza-Klein graviton excitations (G_KK) in the Randall-Sundrum model. Upper limits on the inclusive cross section of Z'(G_KK) → l ⁺ l ^- relative to Z → l ⁺ l ^- are presented. These limits exclude at 95% confidence level a Z' with standard-model-like couplings below 1140GeV, the superstring-inspired Z _φ ' below 887 GeV, and, for values of the coupling parameter k /`(M)̅_Pl of 0.05 (0.1), Kaluza-Klein gravitons below 855 (1079) GeV.