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

Abstract

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