Search for Pair Production of First-Generation Scalar Leptoquarks in pp Collisions at sqrt(s) = 7 TeV

TL;DR

This paper reports a search for first-generation scalar leptoquarks in proton-proton collisions at 7 TeV, setting the most stringent lower mass limit to date at 384 GeV for beta=1, based on CMS data.

Contribution

First direct search for scalar leptoquarks at 7 TeV, establishing the most stringent mass limit to date with CMS data.

Findings

No excess events observed over standard model background.

Lower mass limit for scalar leptoquarks set at 384 GeV for beta=1.

Results constrain theories predicting first-generation scalar leptoquarks.

Abstract

A search for pair production of first-generation scalar leptoquarks is performed in the final state containing two electrons and two jets using proton-proton collision data at sqrt(s)=7 TeV. The data sample used corresponds to an integrated luminosity of 33 inverse picobarns collected with the CMS detector at the CERN LHC. The number of observed events is in good agreement with the predictions for the standard model background processes, and an upper limit is set on the leptoquark pair production cross section times beta^2 as a function of the leptoquark mass, where beta is the branching fraction of the leptoquark decay to an electron and a quark. A 95% confidence level lower limit is set on the mass of a first-generation scalar leptoquark at 384 GeV for beta=1, which is the most stringent direct limit to date.