Disintegration of Light Nuclei by σ-Meson Capture

Abstract
σ-stars in photographic plates are classified into those originated from heavy and light nuclei. The branching ratio of disintegration modes, the a-p ratio, and the energy distribution of emitted particles are measured for light stars. Following characteristic features of light stars are ascertained; 1) the large prong number, 2) the large a-p ratio, 3) the low kinetic energy of emitted particles, and 4) the frequent emission of heavy fragments. The disintegration of C12 into two a-particles and a proton are studied in detail, and the possible emission of Be8 nuclei is discussed. It turns out to be the main disintegration mode, that the rest energy of σ-meson is primarily shared among only a few member of nucleons and the residual part remains in a similar to the excited levels appeared in low energy reactions.