Search for first-generation scalar leptoquarks in $p\overline{p}$ collisions at $\sqrt{s}=1.96\mathrm{TeV}$

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

Figure 1

LQ mass exclusion regions at 95% C.L. as a function of $\mathrm{BR}(\mathrm{LQ}\to eq)$.