Exclusive $\varpi\pi^{0}$ production with muons

Using 160 GeV muon scattering data collected with the COMPASS Experiment at CERN, the exclusive production of $\varpi\pi^{0}$ via virtual photons was studied. Selective population of a peak around 1250 MeV is observed. Possible contributions from spin-parity 1$^{-}$ are searched for, inspecting decay angular correlations. In particular, the orientation of the $\varpi$ decay plane may allow a distinction from the 1$^{+} b_{1}$ (1235) state. Our observation is compared with indications of a $\rho'$(1250) in annihilation and in $\gamma p$.