Search for First Generation Scalar Leptoquark Pairs in {ital p}{bar {ital p}} Collisions at {radical}({ital s}) = 1.8 TeV

We have searched for first generation scalar leptoquark (LQ) pairs in the e{nu}+jets channel using p{bar p} collider data ({integral}Ldt{approx}115 pb{sup {minus}1}) collected by the D0 experiment at the Fermilab Tevatron during 1992{endash}1996. The analysis yields no candidate events. We combine the results with those from the ee+jets and {nu}{nu}+jets channels to obtain 95{percent} confidence level (C.L.) upper limits on the LQ pair production cross section as a function of mass and of {beta} , the branching fraction to a charged lepton. Comparing with the next-to-leading order theory, we set 95{percent} C.L.lower limits on the LQ mass of 225, 204, and 79 GeV/c{sup 2} for {beta}=1 , (1 )/(2) , and 0, respectively. {copyright} {ital 1998} {ital The American Physical Society}