Model independent determination of the spin of the ${\Omega }^{-}$ and its polarization alignment in $\psi (3686)\to {\Omega }^{-}{\bar{\Omega }}^{+}$

Abstract

We present an analysis of the process $\psi (3686)\to {\Omega }^{-}{\bar{\Omega }}^{+}$ (${\Omega }^{-}\to K^{-}\Lambda$, ${\bar{\Omega }}^{+}\to K^{+}\bar{\Lambda }$, $\Lambda \to p{\pi }^{-}$, $\bar{\Lambda }\to \bar{p}{\pi }^{+}$) based on a data set of $448\times 10^6$ $\psi (3686)$ decays collected with the BESIII detector at the BEPCII electron-positron collider. The helicity amplitudes for the process $\psi (3686)\to {\Omega }^{-}{\bar{\Omega }}^{+}$ and the decay parameters of the subsequent decay ${\Omega }^{-}\to K^{-}\Lambda$ $({\bar{\Omega }}^{+}\to K^{+}\bar{\Lambda })$ are measured for the first time by a fit to the angular distribution of the complete decay chain. The branching fraction of $\psi (3686)\to {\Omega }^{-}{\bar{\Omega }}^{+}$ is measured to be $(5.82\pm 0.12\pm 0.24)\times 10^{-5}$, with an improved precision compared to previous measurements.

References in corpus (13)

• Design and Construction of the BESIII Detector
• Polarization and Entanglement in Baryon-Antibaryon Pair Production in Electron-Positron Annihilation
• TopoAna: A generic tool for the event type analysis of inclusive Monte-Carlo samples in high energy physics experiments
• Quantum numbers of the $X(3872)$ state and orbital angular momentum in its ${\rho }^{0}J\psi$ decay
• Determination of the number of $\psi (3686)$ events at BESIII
• Polarization observables in $e^{+}{e}^{-}$ annihilation to a baryon-antibaryon pair
• Hyperon Form Factors & Diquark Correlations
• First Measurements of Timelike Form Factors of the Hyperons, Lambda0, Sigma0, Sigma+, Xi0, Xi-, and Omega-, and Evidence of Diquark Correlations
• Complete measurement of $\Lambda$ electromagnetic form factors
• Measurement of the Spin of the Omega^- Hyperon at BABAR
• Probing CP Violation in Omega->Lambda K->p pi K Decay
• Measurement of the Alpha Asymmetry Parameter for the Omega- to Lambda K- Decay
• Observation of Parity Violation in the Omega-minus -> Lambda + K-minus Decay

Cited by in corpus (12)

• Strong and weak $CP$ tests in sequential decays of polarized ${\Sigma }^0$ hyperons
• Measurement of $e^{+}{e}^{-}\to {\pi }^{+}{\pi }^{-}{D}^{+}{D}^{-}$ cross sections at center-of-mass energies from 4.190 to 4.946 GeV
• Production and decay of polarized hyperon-antihyperon pairs
• Measurements of the branching fractions of $\psi (3686)\to {\bar{\Sigma }}^0\Lambda +c.c.$ and ${\chi }_{cJ(J=0,1,2)}\to \Lambda \bar{\Lambda }$
• Production and decay of hyperons in a transversely polarized electron-positron collider
• Inclusive and semi-inclusive production of spin-3/2 hadrons in $e^{+}{e}^{-}$ annihilation
• Spin Density Matrix for ${\Omega }^{-}$ and its Polarization Alignment in $\psi (3686)\to {\Omega }^{-}{\bar{\Omega }}^{+}$
• Study of the decay $D^{+}\to K^{\ast }(892{)}^{+}{K}_S^0$ in $D^{+}\to K^{+}{K}_S^0{\pi }^0$
• Measurements of the absolute branching fractions of ${\Omega }^{-}$ decays and test of the $\Delta I=1/2$ rule
• Symmetry analysis of charmonium two-body decay
• Tests of CP symmetry in entangled hyperon anti-hyperon pairs at BESIII
• Observation of $\Xi (1530{)}^0$ Polarization and Determination of Its Electric and Magnetic Moments in $\psi (3686)\to \Xi (1530{)}^0\bar{\Xi }(1530{)}^0$