Search for heavy narrow dilepton resonances in pp collisions at s=7 TeV and s=8 TeV

An updated search for heavy narrow resonances decaying to muon or electron pairs using the CMS detector is presented. Data samples from pp collisions at s=7 TeV and 8 TeV at the LHC, with integrated luminosities of up to 5.3 and 4.1 fb−1, respectively, are combined. No evidence for a heavy narrow resonance is observed. The analysis of the combined data sets excludes, at 95% confidence level, a Sequential Standard Model ZSSM′ resonance lighter than 2590 GeV, a superstring-inspired Zψ′ lighter than 2260 GeV, and Kaluza-Klein gravitons lighter than 2390 (2030) GeV, assuming that the coupling parameter k/M¯Pl is 0.10 (0.05). These are the most stringent limits to date.