Search for the rare radiative decay: W → πγ in pp¯ Collisions at √s=1

Abstract

We present a search for the rare radiative decay \wpigamma\ using data corresponding to an integrated luminosity of 4.3 fb ^-1 of proton-antiproton collisions at a center of mass energy of 1.96 TeV collected by the CDF experiment at Fermilab. As no statistically significant signal is observed, we set a 95% confidence level upper limit on the relative branching fraction Γ(W^±→ π^±γ)/Γ(W^±→e^±v) at $6.4\times 10^-5, a factor of 10 improvement over the prev