Evidence for a New Strangeness-One Pseudoscalar Meson

Abstract

The $J^P=0^{-}$ partial waves of the $K\pi \pi$ system in the reactions $K^{\pm }p\to K^{\pm }{\pi }^{+}{\pi }^{-}p$ at 13 GeV are presented. Structure in intensities and relative phase variations suggest the existence of a pseudoscalar resonance, the $K^{\prime }$, with a mass of ∼1400 MeV and a width of ∼250 MeV decaying predominantly into $\epsilon K$.