par Aktas, Adil;Collard, Caroline ;Favart, Laurent ;Janssen, Xavier ;Marage, Pierre ; [et al.]
Référence European Physical Journal C. Particles and Fields, 31, 1, page (17-29)
Publication Publié, 2003
Article révisé par les pairs
Résumé : Multi-electron production is studied at high electron transverse momentum in positron- and electron-proton collisions using the H1 detector at HERA. The data correspond to an integrated luminosity of 115 pb-1. Di-electron and tri-electron event yields are measured. Cross sections are derived in a restricted phase space region dominated by photon-photon collisions. In general good agreement is found with the Standard Model predictions. However, for electron pair invariant masses above 100 GeV, three di-electron events and three tri-electron events are observed, compared to Standard Model expectations of 0.30 ± 0.04 and 0.23 ± 0.04, respectively.