Experimental limit on the decay W±→π±γ at the cern proton-antiproton collider

Abstract We present a search for the decay W ± →π ± γ, using data taken at the CERN proton-antiproton Collider with the UA1 detector and corresponding to an integrated luminosity of 0.7 pb −1 . We do not observe a signal for such a process: hence we obtain an upper limit on the π ± γ decay width of 5.8×10 −2 Γ (W ± →e ± v) (95%CL).