Dergi makalesi Açık Erişim

Study of excited $\Xi $ states in $\psi \left(3686\right)\to {K}^{-}\Lambda {\overline{\Xi }}^{+}+c.c.$

2024    CERN İşbirliği

Based on a sample of $\left(448.1±2.9\right)×{10}^{6}$ $\psi \left(3686\right)$ events collected with the BESIII detector at BEPCII, the decays of $\psi \left(3686\right)\to {K}^{-}\Lambda {\overline{\Xi }}^{+}+c.c.$ with ${\overline{\Xi }}^{+}\to \overline{\Lambda }{\pi }^{+}$, $\overline{\Lambda }\to \overline{p}{\pi }^{+}$ are studied. We investigate the two excited resonances, $\Xi \left(1690{\right)}^{-}$ and $\Xi \left(1820{\right)}^{-}$, which are each observed with large significance ($\gg 10\sigma $) in the ${K}^{-}\Lambda $ invariant mass distributions. A partial wave analysis is performed, and the spin-parities of $\Xi \left(1690{\right)}^{-}$ and $\Xi \left(1820{\right)}^{-}$ are measured to be ${\frac{1}{2}}^{-}$ and ${\frac{3}{2}}^{-}$, respectively. The masses, widths, and product branching fractions of $\Xi \left(1690{\right)}^{-}$ and $\Xi \left(1820{\right)}^{-}$ are also measured.