A search for charge one third third generation leptoquarks in muon channels

Abstract

Includes bibliographical references (pages [93]-100).Leptoquarks are exotic particles that have color, electric charge, and lepton number and appear in extended gauge theories and composite models. Current theory suggests that leptoquarks would come in three different generations corresponding to the three quark and lepton generations. We are searching for charge 1/3 third generation leptoquarks produced in pp̅ collisions at [squareroot s]=1.96 TeV using data collected by the D0 detector. Such leptoquarks would decay into either a tauneutrino plus a b-quark or, if heavy enough, to a tau-lepton plus a t-quark. We present preliminary results on an analysis where both leptoquarks decay into neutrinos, giving a final state with missing energy and two b-quarks using 367 pb⁻¹ of Run II D0 data taken between August 2002 and September 2004. We place upper limits on σ(pp̅ LQL̅Q̅)B² as a function of the leptoquark mass M[sub LQ]. Assuming B = 1, we exclude at the 95% confidence level third generation leptoquarks with M[sub LQ] < 197 GeV/c².Ph.D. (Doctor of Philosophy