High-statistics investigation ofK0K−decay ofA2−produced by 23-GeV/cπ−on hydrogen

We present the results of an experiment to study the reaction ${\pi }^{-}p\to A_2^{-}p$, $A_2^{-}\to K_S^0{K}^{-}$ at 22.4 and 23.9 GeV/c. We have 3346 $K_S^0{K}^{-}$ events in the effective mass region 1.1 to 1.5 GeV, and covering the $\left|t^{\prime }\right|$ interval 0.0 to 1.0 ${(\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{c})}^2$. Because of the low background in this channel, we are able to study various $\left|t^{\prime }\right|$ regions, including the region 0.2 to 0.29 ${(\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{c})}^2$ in which the original split $A_2$ peak was observed. We find no substructure in any region. We have also derived differential and total cross sections. The differential cross sections are well fitted by the form $\frac{d\sigma }{d{t}^{\prime }}=A{t}^{\prime }{e}^{b{t}^{\prime }}$ with $b\approx 7.0$ ${(\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{c})}^{-2\mathrm{}}$. The total cross section is in good agreement with the value derived from other experiments that measure the $A_2^{-}\to {\rho }^0{\pi }^{-}$ decay mode.