Evidence for Top Quark Production in 1.8 Tev Pp Collisions on Behalf of the Cdf Collaboration

This report is a summary of the evidence for top quark production in pp collisions at a center of mass energy of 1.8 TeV which was obtained by the CDF Collaboration earlier this year. The data analyzed corresponds to an integrated luminosity of 19.3 pb ?1 , recorded with the CDF Detector at the Fermilab Tevatron Collider during 1992-1993. Three diierent search channels for t t production are used. A search for dilepton events nds 2 events, while two diierent methods of identifying b-quark jets in events with W+ 3 jets nd 6 and 7 events, respectively. The probability that the observed total yield is consistent with the estimated background of 5:96 +0:49 ?0:44 is 0.26%. Though the statistics are too limited to rmly establish the existence of the top quark, a natural interpretation of the excess is that it is due to t t production. Under this assumption, constrained mass tting of a subset of events yields a top quark mass of 174 10 +13 ?12 GeV/c 2 and a t t production cross section of 13:9 +6:1 ?4:8 pb.