Multi-Electron Production at High Transverse Momenta in ep Collisions at HERA

TL;DR

This paper investigates high transverse momentum multi-electron production in ep collisions at HERA, comparing experimental results with Standard Model predictions and observing some excess events at high invariant masses.

Contribution

It provides the first detailed measurement of multi-electron production at high transverse momenta in ep collisions at HERA, including cross sections and event yields.

Findings

Good overall agreement with Standard Model predictions.

Observation of excess events above 100 GeV invariant mass.

Potential indication of new physics or statistical fluctuation.

Abstract

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 \pm 0.04 and 0.23 \pm 0.04, respectively.