QCD sum rule analysis of local meson-meson currents for the $K(1690)$ state

Yi-Qi Mu, Peng-Wen Xu, Si-Tong Chen +3

The nature of the recently observed $K(1690)$ state, reported by the COMPASS Collaboration as a candidate for a strange crypto-exotic meson with $J^P=0^{-}$, remains unclear. In this…