Amplitude analysis and branching fraction measurement of $J/\psi \to \Lambda {\bar{\Sigma }}^0\eta +c.c$

Abstract

Based on a sample of $(10087\pm 44)\times 10^6$ $J/\psi$ events collected with the BESIII detector, a partial-wave analysis of $J/\psi \to \Lambda {\bar{\Sigma }}^0\eta +c.c$ is performed for the first time. The dominant contributions are found to be excited $\Lambda$ states with $J^P=1/2^{-}$ and $J^P=1/2^{+}$ in the $\eta \Lambda$ mass spectra. The measured masses and widths are $M=1668.8\pm 3.1\pm 21.2$ MeV/$c^2$ and $\Gamma =52.7\pm 4.2\pm 17.8$ MeV for the $\Lambda (1670)$, and $M=1881.5\pm 16.5\pm 20.3$ MeV/$c^2$ and $\Gamma =82.4\pm 18.2\pm 8.9$ MeV for the $\Lambda (1810)$, respectively. The branching fraction is determined to be $\mathcal{B}(J/\psi \to \Lambda {\bar{\Sigma }}^0\eta +c.c)$ = $(3.44\pm 0.11\pm 0.13)\times 10^{-5}$. The first uncertainties are statistical and the second systematic.

References in corpus (18)

• Design and Construction of the BESIII Detector
• The Precision Monte Carlo Event Generator KK For Two-Fermion Final States In e+e- Collisions
• Coherent Exclusive Exponentiation For Precision Monte Carlo Calculations
• Future Physics Programme of BESIII
• Low lying S=-1 excited baryons and chiral symmetry
• Search for hadronic transition ${\chi }_{cJ}\to {\eta }_c{\pi }^{+}{\pi }^{-}$ and observation of ${\chi }_{cJ}\to K\bar{K}\pi \pi \pi$
• The light baryon spectrum in a relativistic quark model with instanton-induced quark forces II. The strange baryon spectrum
• Number of $J/\psi$ events at BESIII
• Determination of the number of $J/\psi$ events with inclusive $J/\psi$ decays
• Dynamical coupled-channels model of $K^{-}p$ reactions (II): Extraction of ${\Lambda }^{\ast }$ and ${\Sigma }^{\ast }$ hyperon resonances
• Study of $J/\psi$ and $\psi (3686)$ decay to $\Lambda \bar{\Lambda }$ and ${\Sigma }^0{\bar{\Sigma }}^0$ final states
• Multichannel parametrization of $\bar{K}N$ scattering amplitudes and extraction of resonance parameters
• Hyperon II: Properties of excited hyperons
• Hadron spectroscopy from strangeness to charm and beauty
• Measurement of $\Lambda$ baryon polarization in $e^{+}{e}^{-}\to \Lambda \bar{\Lambda }$ at $\sqrt{s}=3.773$ GeV
• Partial wave analysis of $\psi (3686)\to K^{+}{K}^{-}\eta$
• Measurement of Branching Fractions of ${\Lambda }_c^{+}\to \eta \Lambda {\pi }^{+}$, $\eta {\Sigma }^0{\pi }^{+}$, $\Lambda (1670){\pi }^{+}$, and $\eta \Sigma (1385{)}^{+}$
• A novel method to test particle ordering and final state alignment in helicity formalism