First observations of $\psi(2S)$ and $\chi_{cJ}(1P)$ decays to four-body final states $h^+h^- K^0_S K^0_S$

Abstract

$\chi_{c0}$, $\chi_{c1}$, and $\chi_{c2}$ decays to $\pi^+\pi^-K^0_SK^0_S$ and $K^+K^-K^0_SK^0_S$, as well as $\psi(2S)$ decay to $\pi^+\pi^-K^0_SK^0_S$ are presented. The branching fractions of these decay channels are determined using $14\times 10^6$ $\psi(2S)$ events collected at BESII/BEPC. The branching fractions of $\chi_{c0},\chi_{c2}\to K^0_SK^0_S$ are measured with improved statistical precision.