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

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

# ${\boldsymbol g}_{{{\boldsymbol A}}}$ $/$ ${\boldsymbol g}_{{{\boldsymbol V}}}$ FOR ${{\boldsymbol \Lambda}}$ $\rightarrow$ ${{\boldsymbol p}}{{\boldsymbol e}^{-}}{{\overline{\boldsymbol \nu}}_{{e}}}$ INSPIRE search

Measurements with fewer than 500 events have been omitted. Where necessary, signs have been changed to agree with our conventions, which are given in the Note on Baryon Decay Parameters'' in the neutron Listings. The measurements all assume that the form factor $\mathit g_{2}$ = 0. See also the footnote on DWORKIN 1990 .
VALUE EVTS DOCUMENT ID TECN  COMMENT
$\bf{ -0.718 \pm0.015}$ OUR AVERAGE
$-0.719$ $\pm0.016$ $\pm0.012$ 37k 1
 1990
SPEC ${{\mathit e}}{{\mathit \nu}}$ angular corr.
$-0.70$ $\pm0.03$ 7111
 1983
SPEC ${{\mathit \Xi}}$ $\rightarrow$ ${{\mathit \Lambda}}{{\mathit \pi}^{-}}$
$-0.734$ $\pm0.031$ 10k 2
 1981
SPEC ${{\mathit e}}{{\mathit \nu}}$ angular correl.
• • • We do not use the following data for averages, fits, limits, etc. • • •
$-0.63$ $\pm0.06$ 817
 1973
OSPK Polarized ${{\mathit \Lambda}}$
1  The tabulated result assumes the weak-magnetism coupling $\mathit w$ ${}\equiv$ ${\mathit g}_{{{\mathit w}}}(0)/{\mathit g}_{{{\mathit v}}}$(0) to be $0.97$, as given by the CVC hypothesis and as assumed by the other listed measurements. However, DWORKIN 1990 $\mathit measures$ $\mathit w$ to be $0.15$ $\pm0.30$, and then ${\mathit g}_{{{\mathit A}}}/{\mathit g}_{{{\mathit V}}}$ = $-0.731$ $\pm0.016$.
2  This experiment measures only the absolute value of ${\mathit g}_{{{\mathit A}}}/{\mathit g}_{{{\mathit V}}}$.
References:
 DWORKIN 1990
PR D41 780 High Statistics Measurement of $\mathit g_{a}$/g$_{v}$ in ${{\mathit \Lambda}}$ $\rightarrow$ ${{\mathit p}}{{\mathit e}^{-}}{{\overline{\mathit \nu}}}$
 BOURQUIN 1983
ZPHY C21 1 Measurements of Hyperon Semileptonic Decays at the CERN Super Proton Synchrotron. 2. The ${{\mathit \Lambda}}$ $\rightarrow$ ${{\mathit p}}{{\mathit e}^{-}}{{\overline{\mathit \nu}}_{{e}}}$ , ${{\mathit \Xi}^{-}}$ $\rightarrow$ ${{\mathit \Lambda}}{{\mathit e}^{-}}{{\overline{\mathit \nu}}_{{e}}}$ , and ${{\mathit \Xi}^{-}}$ $\rightarrow$ ${{\mathit \Sigma}^{0}}{{\mathit e}^{-}}{{\overline{\mathit \nu}}_{{e}}}$ Decay Modes
 WISE 1981
PL 98B 123 Precise Measurement of the Ratio of the Axial Vector Coupling to Vector Coupling in ${{\mathit \Lambda}^{0}}$ $\rightarrow$ ${{\mathit p}}{{\mathit e}^{-}}{{\overline{\mathit \nu}}_{{e}}}$
 ALTHOFF 1973
PL 43B 237 $\beta$ Decay of Polarized ${{\mathit \Lambda}}$ Hyperons III. Correlations in the ${{\mathit \Lambda}}$ Centre-of-Mass System and the Proton Recoil Spectrum