Decay ofH3Λand the Spin Dependence of theΛ-Nucleon Interaction

Abstract

A calculation is made of the fraction of the $\pi$-mesonic decays of the hypertriton ${}_{\Lambda }{}^{}{}_{}{}^{}\mathrm{H}_{}^3{}_{}{}^{}$ which yield the two final products ${\mathrm{He}}^3$ and ${\pi }^{-}$. This fraction is a function of the spin of ${}_{\Lambda }{}^{}{}_{}{}^{}\mathrm{H}_{}^3{}_{}{}^{}$ and of the ratio $\frac{p}{s}$ of the amplitudes for decay of the free $\Lambda$ via the $s$- and $p$-wave channels. The results are compatible with the present experimental data. They indicate that probably $\frac{p}{s}<~1$, and that the spin of ${}_{\Lambda }{}^{}{}_{}{}^{}\mathrm{H}_{}^3{}_{}{}^{}$ is ½, which implies that the singlet $\Lambda$-nucleon interaction is more attractive than the triplet. These results are in agreement with those of a previous calculation by Dalitz for ${}_{\Lambda }{}^{}{}_{}{}^{}\mathrm{H}_{}^4{}_{}{}^{}$.