# ${{\boldsymbol \Lambda}}$ MEAN LIFE

Measurements with an error ${}\geq{}$ $0.1 \times 10^{-10}$ s have been omitted altogether, and only the latest high-statistics measurements are used for the average.

# INSPIRE search

VALUE ($10^{-10}$ s) EVTS DOCUMENT ID TECN  COMMENT
$\bf{ 2.632 \pm0.020}$ OUR AVERAGE  Error includes scale factor of 1.6.
$2.69$ $\pm0.03$ 53k
 1977
SPEC Neutral hyperon beam
$2.611$ $\pm0.020$ 34k
 1975
HBC 0.96$-$1.4 ${\mathrm {GeV/}}\mathit c$ ${{\mathit K}^{-}}{{\mathit p}}$
$2.626$ $\pm0.020$ 36k
 1973
HBC 0.4$-$2.3 ${\mathrm {GeV/}}\mathit c$ ${{\mathit K}^{-}}{{\mathit p}}$
• • • We do not use the following data for averages, fits, limits, etc. • • •
$2.69$ $\pm0.05$ 6582
 1973 B
OSPK ${{\mathit \pi}^{+}}$ ${{\mathit n}}$ $\rightarrow$ ${{\mathit \Lambda}}{{\mathit K}^{+}}$
$2.54$ $\pm0.04$ 4572
 1971 B
HBC ${{\mathit K}^{-}}{{\mathit p}}$ at rest
$2.535$ $\pm0.035$ 8342
 1968
HBC
$2.47$ $\pm0.08$ 2600
 1968
HBC
$2.35$ $\pm0.09$ 916
 1966
HLBC
$2.452$ ${}^{+0.056}_{-0.054}$ 2213
 1966
HBC
$2.59$ $\pm0.09$ 794
 1964
HBC
$2.59$ $\pm0.07$ 1378
 1964
HBC
$2.36$ $\pm0.06$ 2239
 1963
HEBC

${{\mathit \Lambda}}$ mean life (${10^{-10}}$s)
References:
 ZECH 1977
NP B124 413 A Measurement of the Lifetimes of ${{\mathit \Xi}^{0}}$ and ${{\mathit \Lambda}}$ Hyperons
 CLAYTON 1975
NP B95 130 A High Statistics Determination of the ${{\mathit \Lambda}^{0}}$ Mean Lifetime
 ALTHOFF 1973B
NP B66 29 New Determination of the ${{\mathit \Lambda}^{0}}$ Mean Life
 POULARD 1973
PL 46B 135 New Measurement of the ${{\mathit \Lambda}}$ Lifetime
 BALTAY 1971B
PR D4 670 Precision Measurement of the Lifetime and Decay Branching Ratio of the ${{\mathit \Lambda}^{0}}$ Hyperon
 GRIMM 1968
NC 54A 187 A New Determination of the ${{\mathit \Lambda}}$ Lifetime
 HEPP 1968
ZPHY 214 71 A New Determination of the Capture Ratio $_{c}$ = ${ {{\mathit \Sigma}^{-}} {{\mathit p}} \rightarrow {{\mathit \Sigma}^{0}} {{\mathit n}} \over ( {{\mathit \Sigma}^{-}} {{\mathit p}} \rightarrow {{\mathit \Sigma}^{0}} {{\mathit n}} )+( {{\mathit \Sigma}^{-}} {{\mathit p}} \rightarrow {{\mathit \Lambda}} {{\mathit n}} )}$, the ${{\mathit \Lambda}}$-Lifetime and ${{\mathit \Sigma}^{-}}{{\mathit \Lambda}}$ Mass Difference
 BURAN 1966
PL 20 318 Study of the ${{\mathit \Lambda}}{{\mathit p}}$ Effective Mass Spectrum and the ${{\mathit \Lambda}}$ Lifetime
 ENGELMANN 1966
NC 45A 1038 A Lifetime Measurement in a Low-Momentum ${{\mathit \Lambda}}$ Beam
 HUBBARD 1964
PR 135 B183 Lifetimes of the ${{\mathit \Xi}^{-}}$ and ${{\mathit \Xi}^{0}}$ Hyperons
 SCHWARTZ 1964
Thesis UCRL 11360 Associated Production from 1.5 to 2.4 BeV/$\mathit c$
 BLOCK 1963
PR 130 766 Lifetime of the ${{\mathit \Lambda}}$ Hyperon