A search for excited electrons with the Compact Muon Solenoid detector

A search for excited electrons using the CMS detector at the LHC with 36 pb$^{-1}$ of proton-proton collision data recorded at $\sqrt{s}$ = 7 TeV is presented. The search is performed for associated production of an electron and an excited electron followed by the decay of the excited electron to an electron and a photon for a final state of $ e e \gamma$. No excess of events above the standard model expectation is observed. Interpreting the results in the context of production via novel four-fermion contact interactions and the subsequent decay via electroweak processes, upper limits on the production cross section are set. The exclusion region in the compositeness scale, $\Lambda$, and excited electron mass, $M_{e^*}$ , parameter space is extended beyond previously established limits. For $\Lambda$ = 2 TeV, excited electron masses below 760 GeV/c$^2$ are excluded at the 95% confidence level. The cross sections for masses between 200 and 1500 GeV/c$^2$ are limited to be less than 0.21 - 0.16 pb.