Observation of theK0K−Mass Spectrum in theA2-Meson Region

Abstract

We have measured the effective-mass spectrum of $K^{-}K_s^{}{}_{}{}^0$ particles produced in the forward direction in the reaction ${\pi }^{-}+p\to K^{-}+K_s^{}{}_{}{}^0+p$ at $20.3 \frac{\mathrm{GeV}}{c}$. A broad peak correponding to the $A_2$ meson is seen. The shape is fitted well by a single Breit-Wigner curve. A double-pole formula does not fit the data. A narrow peak in the $K^{-}{K}^0$ spectrum is seen at 1.425 GeV.