Search for First Generation Scalar Leptoquarks in the evjj channel 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 a new lower mass limit of 340 GeV for certain decay probabilities, using CMS data.

Contribution

It provides the most stringent direct limits to date on first generation scalar leptoquark masses for beta > 0.05, combining multiple decay channels.

Findings

Observed events agree with standard model predictions.

Set a 95% confidence level lower mass limit of 340 GeV for leptoquarks.

Most stringent limits to date for beta > 0.05.

Abstract

A search for pair-production of first generation scalar leptoquarks is performed in the final state containing an electron, a neutrino, and at least two jets using proton-proton collision data at sqrt(s)=7 TeV. The data were collected by the CMS detector at the LHC, corresponding to an integrated luminosity of 36 inverse picobarns. The number of observed events is in good agreement with the predictions for standard model processes. Prior CMS results in the dielectron channel are combined with this electron+neutrino search. A 95% confidence level combined lower limit is set on the mass of a first generation scalar leptoquark at 340 GeV for beta=0.5, where beta is the branching fraction of the leptoquark to an electron and a quark. These results represent the most stringent direct limits to date for values of beta greater than 0.05.