First measurements of the branching fractions of $J/\psi\to \Xi^0\bar\Lambda K^0_S+c.c.$, $J/\psi\to \Xi^0\bar\Sigma^0 K^0_S+c.c.$, and $J/\psi\to \Xi^0\bar\Sigma^- K^++c.c.$

Abstract

By analyzing $(10087 \pm 44)\times10^6$ $J/\psi$ events collected with the BESIII detector at the BEPCII, the decays $J/\psi\to \Xi^0\bar\Lambda K^0_S+c.c.$, $J/\psi\to \Xi^0\bar\Sigma^0 K^0_S+c.c.$, and $J/\psi\to \Xi^0\bar\Sigma^- K^++c.c.$ are observed for the first time. Their branching fractions are determined to be $\mathcal{B}(J/\psi\to \Xi^0\bar\Lambda K^0_S+c.c.)=(3.76\pm 0.14\pm 0.23)\times10^{-5}$, $\mathcal{B}(J/\psi\to \Xi^0\bar\Sigma^0 K^0_S+c.c.)=(2.24\pm 0.32\pm 0.31)\times10^{-5}$, and $\mathcal{B}(J/\psi\to \Xi^0\bar\Sigma^- K^++c.c.)=(5.64\pm 0.17\pm 0.28)\times10^{-5}$, where the first uncertainties are statistical and the second systematic.