INCLUSIVE NEUTRON, PROTON AND DEUTERON ENERGY SPECTRA FROM STOPPED PI- ABSORPTION IN LI-6, BE-9, O-16 AND AL-27

Inclusive energy spectra (E ⩾ 20MeV) of neutrons, protons, and deuterons emitted after stopped π− absorption in 6Li, 9Be, 16O and 27Al (neutrons only) were measured. Single-neutron emission rates of the order of 10−2 and 10−3 per stopped pion were obtained for 6Li, 9Be, 16O and for 27Al respectively. The experimental data indicate a predominant contribution of two-nucleon absorption mechanism to the neutron and proton spectra for all the studied nuclei, and presence of direct deuterons from cluster-absorption for 6Li. Values of Rnp are deduced, which are consistent with predictions based on the absorption mechanism by a correlated pair of nucleons with pion rescattering.