The $K(1690)$ signal from COMPASS as a strange hybrid state

Bing Chen, Ri-Qing Qian, Xiang Liu

A pseudoscalar resonance structure, denoted as the $K(1690)$, was recently discovered by the COMPASS Collaboration in the scattering reaction $K^{-}+p\to K^{-}{\pi }^{-}{\pi }^{+}+p$. If the $K(1690…