Lifetime of the Λ 0 Hyperon

A precision measurement of the ${\ensuremath{\Lambda}}^{0}$ lifetime has been made in a helium bubble chamber. An exposure to a stopping ${K}^{\ensuremath{-}}$ beam yielded 2239 ${\ensuremath{\Lambda}}^{0}'\mathrm{s}$, with a mean momentum of \ensuremath{\sim}250 MeV/c, which satisfied rigorous selection criteria designed to minimize biases. The mean lifetime was found to be $\ensuremath{\tau}=(2.36\ifmmode\pm\else\textpm\fi{}0.06)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}10}$ sec.