Evidence for Top Quark Production in pp Collisions at vs = 1.8 TeV

Abstract

We summarise a search for the top quark with the Collider Detector at Fermilab (CDF) in a sample of pp collisions at Vs = 1� 8 Te V with an integrated luminosity of 19�3 pb ~ 1. We find 12 events consistent with either two W bosons, or a W boson and at least one b jet. Both of these are signatures for tt events. The probability that the measured yield is consistent with the background is 0�26%. Though the statistics are too limited to establish firmly the existence of the top quark, a natural interpretation of the excess is that it is due to tt production. Under this assumption, constrained fits to individual events yield a top quark mass of 174 � lO:::g GeV / c2? The tt production cross section is measured to be 13.9:::~:~ pb.