# ${{\boldsymbol \Lambda}}$ DECAY PARAMETERS

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

# $\alpha _{−}$ FOR ${{\boldsymbol \Lambda}}$ $\rightarrow$ ${{\boldsymbol p}}{{\boldsymbol \pi}^{-}}$ INSPIRE search

VALUE EVTS DOCUMENT ID TECN  COMMENT
$\bf{ 0.732 \pm0.014}$ OUR AVERAGE  Error includes scale factor of 2.3.
$0.750$ $\pm0.009$ $\pm0.004$ 420k
 2019 BJ
BES3 ${{\mathit J / \psi}}$ to ${{\mathit \Lambda}}{{\overline{\mathit \Lambda}}}$
$0.721$ $\pm0.006$ $\pm0.005$ 1
 2019
CLAS ${{\mathit K}}$ production
• • • We do not use the following data for averages, fits, limits, etc. • • •
$0.584$ $\pm0.046$ 8500
 1975
SPEC
$0.649$ $\pm0.023$ 10325
 1972
OSPK
$0.67$ $\pm0.06$ 3520
 1969
HBC From ${{\mathit \Xi}}$ decay
$0.645$ $\pm0.017$ 10130
 1967
OSPK ${{\mathit \Lambda}}$ from ${{\mathit \pi}^{-}}{{\mathit p}}$
$0.62$ $\pm0.07$ 1156
 1963
CNTR ${{\mathit \Lambda}}$ from ${{\mathit \pi}^{-}}{{\mathit p}}$
1  This is a new analysis based on existing kaon photoproduction data of the CLAS collaboration and using spin algebra constraints.
References:
 ABLIKIM 2019BJ
NATP 15 631
 IRELAND 2019
PRL 123 182301 Kaon Photoproduction and the $\Lambda$ Decay Parameter $\alpha_-$
 ASTBURY 1975
NP B99 30 Measurement of the Differential Cross Section and the Spin Correlation Parameters $\mathit P$, $\mathit A$, and $\mathit R$ in the Backward Peak of ${{\mathit \pi}^{-}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit K}^{0}}{{\mathit \Lambda}}$ at 5 ${\mathrm {GeV/}}\mathit c$
 CLELAND 1972
NP B40 221 A Measurement of the $\beta$-Parameter in the Charged Nonleptonic Decay of the ${{\mathit \Lambda}^{0}}$ Hyperon
 DAUBER 1969
PR 179 1262 Production and Decay of Cascade Hyperons
 OVERSETH 1967
PRL 19 391 Time Reversal Invariance in ${{\mathit \Lambda}}$ Decay
 CRONIN 1963
PR 129 1795 Measurement of the Decay Parameters of the ${{\mathit \Lambda}}$ Particle