A search for excited leptons in pp Collisions at sqrt(s)=7 TeV

A search for excited leptons is carried out with the CMS detector at the LHC, using 36 pb−1 of pp collision data recorded at sqrt(s) =7 TeV. The search is performed for associated production of a lepton and an oppositely charged excited lepton pp→ℓℓ⁎, followed by the decay ℓ⁎→ℓγ, resulting in the ℓℓγ final state, where ℓ=e,μ. No excess of events above the standard model expectation is observed. Interpreting the findings in the context of ℓ⁎ production through four-fermion contact interactions and subsequent decay via electroweak processes, first upper limits are reported for ℓ⁎ production at this collision energy. The exclusion region in the compositeness scale Λ and excited lepton mass Mℓ⁎ parameter space is extended beyond previously established limits. For Λ=Mℓ⁎, excited lepton masses are excluded below 1070 GeV/c2 for e⁎ and 1090 GeV/c2 for μ⁎ at the 95% confidence level.