Multi-lepton production at high transverse momentum at HERA

TL;DR

This paper reports a search for high-transverse-momentum multi-lepton events in ep collisions at HERA, finding results consistent with the Standard Model and measuring di-lepton production cross sections.

Contribution

First comprehensive analysis of multi-lepton production at high transverse momentum in ep collisions at HERA with full data sample.

Findings

Observed events agree with Standard Model predictions.

Measured total and differential di-lepton cross sections.

No significant deviations found in high invariant mass regions.

Abstract

A search for events containing two or more high-transverse-momentum isolated leptons has been performed 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 been compared with the prediction from the Standard Model, searching for possible deviations, especially for multi-lepton events with invariant mass larger than 100 GeV. Good agreement with the Standard Model has been observed. Total and differential cross sections for di-lepton production have been measured in a restricted phase space dominated by photon-photon collisions.