Lifetime of theΛ0Hyperon

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