Search for first-generation scalar leptoquarks in ppbar collisions at sqrt(s)=1.96 TeV

TL;DR

This paper reports a search for first-generation scalar leptoquarks in proton-antiproton collisions at 1.96 TeV, setting new lower mass limits based on the absence of observed signals.

Contribution

It provides the first limits on scalar leptoquark masses at this energy, combining new data with previous results to improve constraints.

Findings

No evidence for leptoquark production was observed.

Lower mass limits are set at 256 GeV/c2 for beta=1.

Lower mass limits are set at 234 GeV/c2 for beta=0.5.

Abstract

We report on a search for pair production of first-generation scalar leptoquarks (LQ) in ppbar collisions at sqrt(s)=1.96 TeV using an integrated luminosity of 252pb-1 collected at the Fermilab Tevatron collider by the D0 detector. We observe no evidence for LQ production in the topologies arising from LQLQbar->eqeq and LQLQbar->eqnuq, and derive 95% C.L. lower limits on the LQ mass as a function of beta, where beta is the branching fraction for LQ->eq. The limits are 241 and 218 GeV/c2 for beta=1 and 0.5, respectively. These results are combined with those obtained by D0 at sqrt(s)=1.8 TeV, which increases these LQ mass limits to 256 and 234 GeV/c2.