First Observation of an Exotic Reggeon

G. D. Alexeev, M. G. Alexeev, C. Alice +180

We present new \compass high-statistics measurements of the peripheral production of $\eta {\pi }^{-}$ and ${\eta }^{\prime }{\pi }^{-}$ pairs in the reactions ${\pi }^{-}p\to {\eta }^{(\prime )}{\pi }^{-}p$. For the first t…