Meson production from diffractive pion dissociation at COMPASS

This paper presents results of $\pi^{-}N\rightarrow\pi^{-}\pi^{-}\pi^{+}N'$ diffractive dissociation events at COMPASS, with 190 GeV$/c$ $\pi^{-}$ beam impinging on lead target during a short pilot run in 2004. A partial wave analysis was performed for the 3$\pi$ final states with four-momentum transfer 0.1 GeV2/c$^{2}\leq t′\leq$ 1.0 GeV$^{2}/c^{2}$, showing well-known resonances and also a state with spin-exotic quantum numbers $J^{PC}=1^{−+}$. Additionally first results of 5$\pi$ final states from 2004 and 3$\pi$ final states from 2008, obtained from a liquid hydrogen target, are presented.