Search for supersymmetry in events with a lepton, a photon, and large missing transverse energy in pp collisions at $ \sqrt {s} = 7 $ TeV

Abstract

A search is performed for an excess of events, over the standard model expectations, with a photon, a lepton, and large missing transverse energy in pp collisions at \( \sqrt {s} = 7 \) TeV. Such events are expected in many new physics models, in particular a supersymmetric theory that is broken via a gauge-mediated mechanism, when the lightest charged and neutral gauginos are mass degenerate. The data sample used in this search corresponds to an integrated luminosity of 35 pb-1 collected with the CMS detector at the LHC. No evidence of such an excess above the standard model backgrounds, dominated by W production, is found. The results are presented as 95% confidence level upper limits on the cross section for a benchmark gauge-mediated scenario, and are then converted into exclusion limits on the squark, gluino, and wino masses.