Observation of $\psi (3686)\to \Xi (1530{)}^{-}\bar{\Xi }(1530{)}^{+}$ and $\Xi (1530{)}^{-}{\bar{\Xi }}^{+}$

Abstract

Using 448.1 $\times$ $10^6$ $\psi (3686)$ events collected with the BESIII detector at BEPCII, we employ a single-baryon tagging technique to make the first observation of $\psi (3686)\to \Xi (1530{)}^{-}\bar{\Xi }(1530{)}^{+}$ and $\Xi (1530{)}^{-}{\bar{\Xi }}^{+}$ decays with a statistical significance of more than 10$\sigma$ and 5.0$\sigma$, respectively. The branching fractions are measured to be $\mathcal{B}$$[\psi (3686)\to \Xi (1530{)}^{-}\bar{\Xi }(1530{)}^{+}]$ = (11.45 $\pm$ 0.40 $\pm$ 0.59) $\times$ $10^{-5}$ and $\mathcal{B}$$[\psi (3686)\to \Xi (1530{)}^{-}{\bar{\Xi }}^{+}]$ = (0.70 $\pm$ 0.11 $\pm$ 0.04) $\times$ $10^{-5}$. The angular distribution parameter for $\psi (3686)\to \Xi (1530{)}^{-}\bar{\Xi }(1530{)}^{+}$ is determined to be $\alpha$ = 0.40 $\pm$ 0.24 $\pm$ 0.06, which agrees with the theoretical predictions within 1$\sigma$. The first uncertainties are statistical, and the second systematic.

8 pages, 8 figures, Consistent with paper published in Phys. Rev. D 100, 051101(R) (2019)