Mesonic Decay of a Lithium Hyperfragment

The mesonic decay of a nuclear fragment in a photographic emulsion is described. The event is most simply interpreted as the disintegration of a ${\mathrm{Li}}^{7*}$ hyperfragment according to the scheme ${\mathrm{Li}}^{7*}\to {\mathrm{He}}^4+{\mathrm{H}}^2+{\mathrm{H}}^1+{\pi }^{-}$. The binding energy of the ${\Lambda }^0$ particle in the fragment is 4.4±1.0 Mev.