Multi-lepton production at high transverse momentum at HERA

摘要

A search for events containing two or more high-transverse-momentum isolated leptons has beenperformed in ep collisions with the ZEUS detector at HERA using the full collected data sample,corresponding to an integrated luminosity of 480 pb-1. The number of observed events has beencompared with the prediction from the Standard Model, searching for possible deviations, especially formulti-lepton events with invariant mass larger than 100 GeV. Good agreement with the Standard Modelhas been observed. Total and differential cross sections for di-lepton production have been measured ina restricted phase space dominated by photon-photon collisions.