Associated production of an isolated large-transverse-momentum lepton (electron or muon) and two jets at the Cern $p\bar p$ collider

Abstract A clear signal is observed for the production of an isolated large-transverse-momentum lepton in association with two or three centrally produced jets. The two-jet events cluster around the W ± mass, indicating a novel decay of the Intermediate Vector Boson. The rate and features of these events are not consistent with expectations of known quark decays (charm, bottom). They are, however, in agreement with the process W → t b followed by t → bl v , where t is the sixth quark (top) of the weak Cabibbo current. If this is indeed so, the bounds on the mass of the top quark are 30 GeV / c 2 m t GeV / c 2 .