Search for First and Second Generation Leptoquarks at D\O

Abstract

A search for first and second generation leptoquarks has been done with the D\O \ detector at Fermilab's p\={p} collider with $\sqrt{s}=1.8$ TeV. 95\% C.L. mass limits for first generation scalar leptoquarks have been recently published. The number for the total integrated luminosity used in the first generation leptoquark analysis has changed (via a change in the total inelastic cross section) since the publication. The new limits are 130 GeV/c$^{2}$ and 116 GeV/c$^{2}$ for a respective 100\% and 50\% decay branching ratio of the leptoquark to electron. The preliminary upper limit on the cross section from the search for second generation scalar leptoquarks has set limits on the mass of the second generation leptoquark of 97 GeV/c$^{2}$ for 100\% branching to muons and 80 GeV/c$^{2}$ for 50\% branching. In contrast with leptoquark detection thresholds at e$^{+}$e$^{-}$ and e-p machines, these limits are independent of the unknown coupling of the leptoquark to leptons and quarks.