${{\boldsymbol \Xi}^{0}}$ DECAY PARAMETERS

See the ``Note on Baryon Decay Parameters'' in the neutron Listings.

$\alpha $ FOR ${{\boldsymbol \Xi}^{0}}$ $\rightarrow$ ${{\boldsymbol \Sigma}^{0}}{{\boldsymbol \gamma}}$ INSPIRE search

See the note above on ``Radiative Hyperon Decays.''
VALUE EVTS DOCUMENT ID TECN  COMMENT
$\bf{ -0.69 \pm0.06}$ OUR AVERAGE
$-0.729$ $\pm0.030$ $\pm0.076$ 15k 1
BATLEY
2010B
NA48 ${{\mathit p}}$ Be, 400 GeV
$-0.63$ $\pm0.08$ $\pm0.05$ 4045
ALAVI-HARATI
2001C
KTEV ${{\mathit p}}$ nucleus, 800 GeV
• • • We do not use the following data for averages, fits, limits, etc. • • •
$+0.20$ $\pm0.32$ $\pm0.05$ 85 2
TEIGE
1989
SPEC FNAL hyperons
1  BATLEY 2010B also measured the ${{\overline{\mathit \Xi}}^{0}}$ $\rightarrow$ ${{\overline{\mathit \Sigma}}^{0}}{{\mathit \gamma}}$ asymmetry to be $-0.786$ $\pm0.104$ (no systematic error given) with 1404 events.
2  This result has been withdrawn, due to an error. See the erratum, TEIGE 2002 .
  References:
BATLEY 2010B
PL B693 241 New Precise Measurements of the ${{\mathit \Xi}^{0}}$ $\rightarrow$ ${{\mathit \Lambda}}{{\mathit \gamma}}$ and ${{\mathit \Xi}^{0}}$ $\rightarrow$ ${{\mathit \Sigma}^{0}}{{\mathit \gamma}}$ Decay Asymmetries
ALAVI-HARATI 2001C
PRL 86 3239 Measurement of the Branching Ratio and Asymmetry of the Decay ${{\mathit \Xi}^{0}}$ $\rightarrow$ ${{\mathit \Sigma}^{0}}{{\mathit \gamma}}$
TEIGE 1989
PRL 63 2717 Measurement of the ${{\mathit \Xi}^{0}}$ $\rightarrow$ ${{\mathit \Sigma}^{0}}{{\mathit \gamma}}$ Branching Ratio and Asymmetry Parameter