Leptoquark Searches at the Tevatron.pdf

Lepto quark Searches at the Tevatron Guoliang Wang D Col laborationDept of Physics Florida State University For the D and CDF Col laborations Abstract The D and CDF exp eriments have searched for the pair pro duction of scalar lepto quarks for all three generations and for vector lepto quarks with YangMills couplings for the rst generation at the Fermilab pp collider at ps TeV In each of the channels searched the numb er of candidate events is in agreement with background estimations Comparing CL upp er limits on the LQ pro duction cross sections with LO theoretical calculations lower limits on the masses of lepto quarks are obtained for each generation INTR ODUCTION Lepto quarks LQ are exotic particles which are present in many theories b eyond the standard mo del SM They are colortriplet b osons which couple to b oth quarks and leptons and have fractional charge spin or and baryon and lepton quantum numb ers Constraints on avorchanging neu tral current F CNCs and rare decays indicate that lepto quarks with masses accessible at the Tevatron couple only within a single generation Because the pair pro duction of lepto quarks is the dominant pro cess at the Tevatron b oth the D and CDF collab orations have p erformed searches for pair pro duced LQs Both have published results of searches for rst and second genera tion scalar lepto quarks using Run Ia data In this pap er results are presented from recent searches for rst second and third generation scalar LQs and the rst generation vector LQs using times larger data samples FIRST GENERATION SCALAR LQ SEARCHES If after pair pr