ATLAS, CollaborationCollaborationATLASAgustoni, MarcoMarcoAgustoniAncu, LucianLucianAncuBattaglia, AndreasAndreasBattagliaBeck, Hans PeterHans PeterBeck0000-0001-7212-1096Borer, ClaudiaClaudiaBorerEreditato, AntonioAntonioEreditatoGallo, ValentinaValentinaGalloHaug, SigveSigveHaug0000-0003-0442-3361Kabana, SonjaSonjaKabanaKruker, TobiasTobiasKrukerMarti, LukasLukasMartiPretzl, Klaus-PeterKlaus-PeterPretzlSchneider, BasilBasilSchneiderSciacca, GianfrancoGianfrancoSciaccaWeber, MichaelMichaelWeber0000-0002-2770-90312024-10-232024-10-232013https://boris-portal.unibe.ch/handle/20.500.12422/126284We present a search for a light (mass < 2 GeV) boson predicted by Hidden Valley supersymmetric models that decays into a final state consisting of collimated muons or electrons, denoted "lepton-jets". The analysis uses 5 fb(-1) of root s = 7 TeV proton-proton collision data recorded by the ATLAS detector at the Large Hadron Collider to search for the following signatures: single lepton-jets with at least four muons; pairs of lepton-jets, each with two or more muons; and pairs of lepton-jets with two or more electrons. This study finds no statistically significant deviation from the Standard Model prediction and places 95% confidence-level exclusion limits on the production cross section times branching ratio of light bosons for several parameter sets of a Hidden Valley model.en500 - Science::530 - Physicsarticle10.7892/boris.583911212.5409v200031531690000810.1016/j.physletb.2013.01.034