Search for First-Generation Scalar Leptoquarks in $\bm{p \bar{p}}$ collisions at $\sqrt{s}$=1.96 TeV

Abstract

We report on a search for pair production of first-generation scalar leptoquarks ($LQ$) in $p \bar{p}$ collisions at $\sqrt{s}$=1.96 TeV using an integrated luminosity of 203 $pb^{-1}$ collected at the Fermilab Tevatron collider by the CDF experiment. We observe no evidence for $LQ$ production in the topologies arising from $LQ \bar{LQ} \to eqeq$ and $LQ \bar{LQ} \to eq νq$, and derive 95% C.L. upper limits on the $LQ$ production cross section. %as a function of $β$, where $β$ is the branching fraction for $LQ \to eq$. The results are combined with those obtained from a separately reported CDF search in the topology arising from $LQ\bar{LQ} \to νq νq$ and 95% C.L. lower limits on the LQ mass as a function of $β= BR(LQ \to eq) $ are derived. The limits are 236, 205 and 145 GeV/c$^2$ for $β$ = 1, $β$ = 0.5 and $β$ = 0.1, respectively.