Multi-lepton production in ep collisions at HERA

Multi-lepton events containing at least two electrons or two muons are studied in ep scattering at HERA using HERA I data samples at centre of mass energies of √s = 301 GeV and √s = 319 GeV and corresponding to integrated luminosities of 115 pb-1 (H1) and 130 pb-1 (ZEUS). Cross sections are derived from H1 data samples for the production of di-muons at √s = 319 GeV and for electron pair production. In di- and tri-lepton events, mass distributions are studied. High-mass multi-electron events are observed in a region where the Standard Model prediction is smaller. A possible interpretation of this excess in terms of doubly charged Higgs boson production is ruled out