On theγ-Ray Spectrum Resulting from the Absorption ofπ-Mesons in Deuterium

The $\gamma$-ray spectrum resulting from the reaction ${\pi }^{-}+\mathrm{D}\to 2n+\gamma$ has been shown to depend strongly on the nature of the $n-n$ interaction and has been calculated for several values of the $n-n$ scattering length. A comparison of the theoretical cross section with preliminary experiments by Aamodt, Panofsky, and Phillips indicates: (1) an upper limit of approximately 200 kev can be put on the binding energy of the di-neutron; (2) photomeson production involves an interaction with the nucleon spin.