${{\mathit \Sigma}^{+}}$ DECAY PARAMETERS

See the ``Note on Baryon Decay Parameters'' in the neutron Listings. A few early results have been omitted.

${{\overline{\mathit \alpha}}_{{{0}}}}$ FOR ${{\overline{\mathit \Sigma}}^{-}}$ $\rightarrow$ ${{\overline{\mathit p}}}{{\mathit \pi}^{0}}$

INSPIRE   JSON  (beta) PDGID:
S019A1
S019A1
VALUE EVTS DOCUMENT ID TECN  COMMENT
$0.999$ $\pm0.011$ $\pm0.004$ 1.07M 1
ABLIKIM
2025BT
 
BES3 ${{\mathit J / \psi}}$ $/$ ${{\mathit \psi}{(2S)}}$ $\rightarrow$ ${{\mathit \Sigma}^{+}}{{\overline{\mathit \Sigma}}^{-}}$
• • We do not use the following data for averages, fits, limits, etc. • •
$0.990$ $\pm0.037$ $\pm0.011$ 93k 2
ABLIKIM
2020X
 
BES3 ${{\mathit J / \psi}}$ $/$ ${{\mathit \psi}{(2S)}}$ $\rightarrow$ ${{\mathit \Sigma}^{+}}{{\overline{\mathit \Sigma}}^{-}}$
1  ABLIKIM 2025BT uses production through ${{\mathit e}^{+}}$ ${{\mathit e}}$ $\rightarrow$ ${{\mathit J / \psi}}$ $\rightarrow$ ${{\mathit \Sigma}^{+}}{{\overline{\mathit \Sigma}}^{-}}$ and ${{\mathit e}^{+}}$ ${{\mathit e}}$ $\rightarrow$ ${{\mathit \psi}{(2S)}}$ $\rightarrow$ ${{\mathit \Sigma}^{+}}{{\overline{\mathit \Sigma}}^{-}}$, with $1016678$ $\pm1398$ and $53293$ $\pm299$ events, respectively.
2  ABLIKIM 2020X uses production through ${{\mathit e}^{+}}$ ${{\mathit e}}$ $\rightarrow$ ${{\mathit J / \psi}}$ $\rightarrow$ ${{\mathit \Sigma}^{+}}{{\overline{\mathit \Sigma}}^{-}}$ and ${{\mathit e}^{+}}$ ${{\mathit e}}$ $\rightarrow$ ${{\mathit \psi}{(2S)}}$ $\rightarrow$ ${{\mathit \Sigma}^{+}}{{\overline{\mathit \Sigma}}^{-}}$, with 87,815 and 5,327 events, respectively. Note that the reported values of decay parameters ${{\mathit \alpha}_{{{0}}}}$ of ${{\mathit \Sigma}^{+}}$ and ${{\overline{\mathit \alpha}}_{{{0}}}}$ of ${{\overline{\mathit \Sigma}}^{-}}$ are correlated.
References