Exclusive hadronic $W$ decay: $W \to \pi \gamma$ and $W \to \pi^+ \pi^+ \pi^-$

In this talk I will present results which assess the possibility of the LHC observing the decays W→πγ and W→π+π+π− . No exclusive hadronic decay of a fundamental standard model boson has ever been observed before and, at the LHC, the huge QCD background and trigger challenges present serious difficulties in making such measurements. The latter problem can be addressed by studying W s in a tt‾ environment, exploiting the triggering opportunities this brings, and I discuss the use of an isolation technique – requiring single particle jets – which can help to separate signal from the QCD background. The conclusions drawn here are that while the W→πγ decay seems unlikely to be measured at the LHC, W→π+π+π− could be observed by the end of the high luminosity run.