Search for First-Generation Scalar Leptoquarks in $\mathbf{p}\bar{\mathbf{p}}$ 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 $p{b}^{-1}$ collected at the Fermilab Tevatron collider by the CDF experiment. We observe no evidence for $LQ$ production in the topologies arising from $LQ\overline{LQ}\to eqeq$ and $LQ\overline{LQ}\to eq\hat{I}½q$, and derive 95% C.L. upper limits on the $LQ$ production cross section. %as a function of ${\hat{I}}^2$, where ${\hat{I}}^2$ 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 $LQ\overline{LQ}\to \hat{I}½q\hat{I}½q$ and 95% C.L. lower limits on the LQ mass as a function of ${\hat{I}}^2=BR(LQ\to eq)$ are derived. The limits are 236, 205 and 145 GeV/c${}^2$ for ${\hat{I}}^2$ = 1, ${\hat{I}}^2$ = 0.5 and ${\hat{I}}^2$ = 0.1, respectively.

submitted to PRL