Search for Isolated Leptons with Missing pt and Multi-leptons at HERA

TL;DR

This paper reports a comprehensive search for isolated leptons with missing transverse momentum and multi-lepton events in HERA e±-p collision data, comparing observations to Standard Model predictions to identify potential new physics signals.

Contribution

It provides the first full analysis of the complete HERA high-energy data set for isolated leptons and multi-leptons, testing the Standard Model with no observed deviations.

Findings

No significant deviation from Standard Model predictions.

Measured yields of single, di-, and tri-lepton events consistent with expectations.

Established limits on new physics scenarios involving leptons.

Abstract

A search for events with one or more isolated leptons in the final state is performed on a data sample collected in e+-p collisions with the H1 and ZEUS detectors at the HERA collider. The data sample corresponds to an integrated luminosity of ~1 fb-1, representing the full HERA high-energy data set. The yields of single, di- and tri-lepton events are measured and compared to the Standard Model predictions, looking for possible deviations. No significant discrepancy with respect to the Standard Model expectations is observed.