Search for pair production of second generation scalar leptoquarks

Abstract We report on a search for the pair production of second generation scalar leptoquarks ( LQ ) in p p ¯ collisions at the center of mass energy s = 1.96 TeV using a data set corresponding to an integrated luminosity of 1.0 fb −1 collected with the DO experiment at the Fermilab Tevatron Collider. Topologies arising from the LQ LQ ¯ → μ q ν q and LQ LQ ¯ → μ q μ q decay modes are investigated. No excess of data over the standard model prediction is observed and upper limits on the leptoquark pair production cross section are derived at the 95% C.L. as a function of the leptoquark mass and the branching fraction β for the decay LQ → μ q . These are interpreted as lower limits on the leptoquark mass as a function of β . For β = 1 ( 0.5 ) , scalar second generation leptoquarks with masses up to 316 GeV (270 GeV) are excluded.