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

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.