# ${{\boldsymbol \Xi}^{-}}$ DECAY PARAMETERS

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

# $\phi$ ANGLE FOR ${{\boldsymbol \Xi}^{-}}$ $\rightarrow$ ${{\boldsymbol \Lambda}}{{\boldsymbol \pi}^{-}}$ (tan$\phi$ = $\beta /\gamma$) INSPIRE search

VALUE ($^\circ{}$) EVTS DOCUMENT ID TECN  COMMENT
$\bf{ -2.1 \pm0.8}$ OUR AVERAGE
$-2.39$ $\pm0.64$ $\pm0.64$ 144M 1
 2004
HYCP ${{\mathit p}}$ Cu, 800 GeV
$-1.61$ $\pm2.66$ $\pm0.37$ 1.35M 2
 2003
E756 ${{\mathit p}}$ Be, 800 GeV
$5$ $\pm10$ 11k
 1985 B
LASS ${{\mathit K}^{-}}{{\mathit p}}$
$14.7$ $\pm16.0$ 21k 3
 1985
MPS 5 ${\mathrm {GeV/}}\mathit c$ ${{\mathit K}^{-}}{{\mathit p}}$
$11$ $\pm9$ 4303
 1974
HBC 1.75 ${\mathrm {GeV/}}\mathit c$ ${{\mathit K}^{-}}{{\mathit p}}$
$5$ $\pm16$ 2436
 1974
OSPK 1.8 ${\mathrm {GeV/}}\mathit c$ ${{\mathit K}^{-}}{{\mathit p}}$
$-14$ $\pm11$ 2781
 1969
HBC Uses $\alpha _{{{\mathit \Lambda}}}$ = $0.647$ $\pm0.020$
$0$ $\pm12$ 1004 4
 1966
HBC
• • • We do not use the following data for averages, fits, limits, etc. • • •
$-26$ $\pm30$ 2724
 1970 B
OSPK
$0$ $\pm20.4$ 364 4
 1966
HBC Using $\alpha _{{{\mathit \Lambda}}}=0.62$
$54$ $\pm30$ 356 4
 1964 B
HBC
1  From this result and $\alpha _{{{\mathit \Xi}}}$, HUANG 2004 gets $\beta _{{{\mathit \Xi}}}$ = $-0.037$ $\pm0.011$ $\pm0.010$ and $\gamma _{{{\mathit \Xi}}}$ = $0.888$ $\pm0.0004$ $\pm0.006$. And the strong p$-$s phase difference for ${{\mathit \Lambda}}{{\mathit \pi}^{-}}$ scattering is ($4.6$ $\pm1.4$ $\pm1.2)^\circ{}$.
2  From this result and $\alpha _{{{\mathit \Xi}}}$, CHAKRAVORTY 2003 obtains $\beta _{{{\mathit \Xi}}}$ = $-0.025$ $\pm0.042$ $\pm0.006$ and $\gamma _{{{\mathit \Xi}}}$ = $0.889$ $\pm0.001$ $\pm0.007$. And the strong p$-$s phase difference for ${{\mathit \Lambda}}{{\mathit \pi}^{-}}$ scattering is ($3.17$ $\pm5.28$ $\pm0.73)^\circ{}$.
3  BENSINGER 1985 used $\alpha _{\Lambda }$ = $0.642$ $\pm0.013$.
4  The errors have been multiplied by 1.2 due to approximations used for the ${{\mathit \Xi}}$ polarization; see DAUBER 1969 for a discussion.
References:
 HUANG 2004
PRL 93 011802 New Measurement of ${{\mathit \Xi}^{-}}$ $\rightarrow$ ${{\mathit \Lambda}}{{\mathit \pi}^{-}}$ Decay Parameters
 CHAKRAVORTY 2003
PRL 91 031601 Measurement of Decay Parameters for ${{\mathit \Xi}^{-}}$ $\rightarrow$ ${{\mathit \Lambda}}{{\mathit \pi}^{-}}$ Decay
 ASTON 1985B
PR D32 2270 Inclusive Production of Multistrange Hyperons from 11 ${\mathrm {GeV/}}\mathit c$ ${{\mathit K}^{-}}{{\mathit p}}$ Interactions
 BENSINGER 1985
NP B252 561 Measurement of Decay Parameters and Polarization in Inclusive ${{\mathit \Xi}^{-}}$ Production from ${{\mathit K}^{-}}{{\mathit p}}$ Interactions
 BALTAY 1974
PR D9 49 Properties of ${{\mathit \Xi}^{-}}$ and ${{\mathit \Xi}^{0}}$ Hyperons
 COOL 1974
PR D10 792 Measurement of the Magnetic Moment and of the Decay Parameters of the ${{\mathit \Xi}^{-}}$ Hyperon
 BINGHAM 1970B
PR D1 3010 Study of the Decay Parameters and Magnetic Moment of the ${{\mathit \Xi}^{-}}$
 DAUBER 1969
PR 179 1262 Production and Decay of Cascade Hyperons
 BERGE 1966
PR 147 945 Some Properties of ${{\mathit \Xi}^{-}}$ and ${{\mathit \Xi}^{0}}$ Hyperons Produced in ${{\mathit K}^{-}}{{\mathit p}}$ Interactions between 1.05 and 1.7 ${\mathrm {GeV/}}\mathit c$
 LONDON 1966
PR 143 1034 ${{\mathit K}^{-}}{{\mathit p}}$ Interaction at 2.24 BeV
 CARMONY 1964B
PRL 12 482 Properties of ${{\mathit \Xi}}$ Hyperons