A search for new long-lived particles decaying to leptons is presented using proton-proton collisions produced by the LHC at sqrt(s) = 8 TeV. Data used for the analysis were collected by the CMS detector and correspond to an integrated luminosity of 19.7 inverse femtobarns. Events are selected with an electron and a muon that have transverse impact parameter values between 0.02 cm and 2 cm. The search has been designed to be sensitive to a wide range of models with nonprompt e-mu final states. Limits are set on the "displaced supersymmetry" model, with pair production of top squarks decaying into an e-mu final state via R-parity-violating interactions. The results are the most restrictive to date on this model, with the most stringent limit being obtained for a top squark lifetime corresponding to c tau = 2 cm, excluding masses below 790 GeV at 95% confidence level.
CMS, Basegmez, S., Beluffi, C., Bruno, G., Castello, R., Caudron, A., Ceard, L., Da Silveira, G. G., Delaere, C., Du Pree, T., Favart, D., Forthomme, L., Giammanco, A., Hollar, J., Jafari, A., Jez, P., Komm, M., Lemaitre, V., Nuttens, C., et al. (2015). Search for Displaced Supersymmetry in events with an electron and a muon with large impact parameters. Physical Review Letters, 114, 61801. https://doi.org/10.1103/PhysRevLett.114.061801 (Original work published 2015)