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

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

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

INSPIRE   PDGID:

S019A0

VALUE EVTS DOCUMENT ID TECN  COMMENT $\bf{ -0.982 \pm0.014}$ OUR FIT $\bf{ -0.982 {}^{+0.016}_{-0.013}}$ OUR AVERAGE $-0.998$ $\pm0.037$ $\pm0.009$ 93k 1 ABLIKIM 2020 X BES3 ${{\mathit J / \psi}}$ $/$ ${{\mathit \psi}{(2S)}}$ $\rightarrow$ ${{\mathit \Sigma}^{+}}{{\overline{\mathit \Sigma}}^{-}}$ $-0.945$ ${}^{+0.055}_{-0.042}$ 1259 2 LIPMAN 1973 OSPK ${{\mathit \pi}^{+}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit \Sigma}^{+}}$ $-0.940$ $\pm0.045$ 16k BELLAMY 1972 ASPK ${{\mathit \pi}^{+}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit \Sigma}^{+}}{{\mathit K}^{+}}$ $-0.98$ ${}^{+0.05}_{-0.02}$ 1335 3 HARRIS 1970 OSPK ${{\mathit \pi}^{+}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit \Sigma}^{+}}{{\mathit K}^{+}}$ $-0.999$ $\pm0.022$ 32k BANGERTER 1969 HBC ${{\mathit K}^{-}}{{\mathit p}}$ 0.4 ${\mathrm {GeV/}}\mathit c$ 1  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. 2  Decay protons scattered off aluminum. 3  Decay protons scattered off carbon.

References:

ABLIKIM 2020X PRL 125 052004 $\Sigma^{+}$ and $\bar{\Sigma}^-$ polarization in the $J/\psi$ and $\psi(3686)$ decays LIPMAN 1973 PL 43B 89 Test of the ${{\mathit \Delta}}\mathit I={1\over 2}$ Rule and the Lee-Sugawara Relation in the Decay ${{\mathit \Sigma}^{+}}$ $\rightarrow$ ${{\mathit p}}{{\mathit \pi}^{0}}$ BELLAMY 1972 PL 39B 299 Polarization in the Reaction ${{\mathit \pi}^{+}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit K}^{+}}{{\mathit \Sigma}^{+}}$ at 1.11 ${\mathrm {GeV/}}\mathit c$ HARRIS 1970 PRL 24 165 Proton Polarization in ${{\mathit \Sigma}^{+}}$ $\rightarrow$ ${{\mathit p}}{{\mathit \pi}^{0}}$ BANGERTER 1969 Thesis UCRL 19244 Nonleptonic Decay of ${{\mathit \Sigma}}$ Hyperons

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