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

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

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

INSPIRE   JSON  (beta) PDGID:
S019AG
VALUE EVTS DOCUMENT ID TECN  COMMENT
$\bf{ -0.69 \pm0.05}$ OUR AVERAGE
$-0.652$ $\pm0.056$ $\pm0.020$ 2.5k 1
ABLIKIM
2023Y
 BES3 ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit J / \psi}}$ $\rightarrow$ ${{\mathit \Sigma}}{{\overline{\mathit \Sigma}}}$
$-0.720$ $\pm0.086$ $\pm0.045$ 35k 2
FOUCHER
1992
SPEC ${{\mathit \Sigma}^{+}}$ 375 GeV
$-0.86$ $\pm0.13$ $\pm0.04$ 190
KOBAYASHI
1987
CNTR ${{\mathit \pi}^{+}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit \Sigma}^{+}}{{\mathit K}^{+}}$
$-0.53$ ${}^{+0.38}_{-0.36}$ 46
MANZ
1980
HBC ${{\mathit K}^{-}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit \Sigma}^{+}}{{\mathit \pi}^{-}}$
$-1.03$ ${}^{+0.52}_{-0.42}$ 61
GERSHWIN
1969B
 HBC ${{\mathit K}^{-}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit \Sigma}^{+}}{{\mathit \pi}^{-}}$
1  This value is quoted by ABLIKIM 2023Y for the simultaneous fit to ${{\mathit \Sigma}}$ $\rightarrow$ ${{\mathit p}}{{\mathit \gamma}}$ and ${{\overline{\mathit \Sigma}}}$ $\rightarrow$ ${{\overline{\mathit p}}}{{\mathit \gamma}}$ assuming no $\mathit CP$ violation. Individual values are given as $-0.587$ $\pm0.082$ and $0.710$ $\pm0.076$, respectively.
2  See TIMM 1995 for a detailed description of the analysis.
References