${{\mathit \Sigma}^{+}}$ 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   PDGID:
S019AG
VALUE EVTS DOCUMENT ID TECN  COMMENT
$\bf{ -0.76 \pm0.08}$ OUR AVERAGE
$-0.720$ $\pm0.086$ $\pm0.045$ 35k 1
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  See TIMM 1995 for a detailed description of the analysis.
References:
FOUCHER 1992
PRL 68 3004 Measurement of the Asymmetry Parameter in the Hyperon Radiative Decay ${{\mathit \Sigma}^{+}}$ $\rightarrow$ ${{\mathit p}}{{\mathit \gamma}}$
KOBAYASHI 1987
PRL 59 868 New Measurement of the Asymmetry Parameter for the ${{\mathit \Sigma}^{+}}$ $\rightarrow$ ${{\mathit p}}{{\mathit \gamma}}$ Decay
MANZ 1980
PL 96B 217 A New Measurement of ${{\mathit \Sigma}^{+}}$ $\rightarrow$ ${{\mathit p}}{{\mathit \gamma}}$ Decay Properties
GERSHWIN 1969B
PR 188 2077 Asymmetry Parameter and Branching Ratio of ${{\mathit \Sigma}^{+}}$ $\rightarrow$ ${{\mathit p}}{{\mathit \gamma}}$
Also
Thesis UCRL 19246 Asymmetry Parameters in ${{\mathit \Sigma}^{-}}$ $\rightarrow$ ${{\mathit n}}{{\mathit e}^{-}}{{\overline{\mathit \nu}}_{{e}}}$ and ${{\mathit \Sigma}^{+}}$ $\rightarrow$ ${{\mathit p}}{{\mathit \gamma}}$