Study of the reactions $\bar{n}p\to 2{\pi }^{+}{\pi }^{-}$, $2{\pi }^{+}{\pi }^{-}{\pi }^0$, and $2{\pi }^{+}{\pi }^{-}2{\pi }^0$ using $J/\psi \to p{\pi }^{-}\bar{n}$

BESIII Collaboration, M. Ablikim, M. N. Achasov +688

We report an experimental investigation of the reactions $\bar{n}p\to 2{\pi }^{+}{\pi }^{-}$, $\bar{n}p\to 2{\pi }^{+}{\pi }^{-}{\pi }^0$, and $\bar{n}p\to 2{\pi }^{+}{\pi }^{-}2{\pi }^0$ using $(10.087 \pm 0.0…