Associated production of lepton and jets

A clean signal has been observed for the production of an isolated large-transverse-momentum lepton in association with two jets. The rate and feature of these events are not consistent with expectation from known quark decays (charm, bottom). There are consistent as being the manifestation of t-quark decay, t being the sixth quark from Cabibbo current, through 2 processes W → t anti b or p anti p → t anti t, followed by semi-leptonic decay of the t-quark. That interpretation bounds the mass of the top quark in the range 30 < msub(t) < 50 GeV/c2. (author)