Search for First Generation Leptoquarks in ep Collisions at HERA

TL;DR

This paper reports a comprehensive search for first generation scalar and vector leptoquarks in ep collisions at HERA, using the full H1 dataset, setting new mass exclusion limits up to 800 GeV.

Contribution

It provides the first extensive search for first generation leptoquarks at HERA with the full dataset, establishing new mass exclusion limits.

Findings

No evidence for leptoquark production was observed.

Leptoquarks with masses up to 800 GeV are excluded at 95% CL for lambda=0.3.

The results constrain leptoquark models significantly.

Abstract

A search for first generation scalar and vector leptoquarks produced in ep collisions is performed by the H1 experiment at HERA. The full H1 data sample is used in the analysis, corresponding to an integrated luminosity of 446 pb^-1. No evidence for the production of leptoquarks is observed in final states with a large transverse momentum electron or with large missing transverse momentum, and constraints on leptoquark models are derived. For leptoquark couplings of electromagnetic strength lambda=0.3, first generation leptoquarks with masses up to 800 GeV are excluded at 95% confidence level.