2+ States of 8Be

摘要: Analysis by many-level R-matrix theory of the d-wave "'-'" scattering phase shift suggests existence broad 2+ excited states 8Be, but their properties depend sensitively on assumed channel radius a2. A simultaneous fit to 9Be(p, d)8Be deuteron spectrum near 2, 9 MeV peak requires a2 "'" 7·1 fm, while a ",-particle spectra following 8Li and 8B p-decays 6· 7 fm. For best overall with = 6·75 first state is at 2· 84 excitation energy width half maximum 1·30 MeV. It shown that data from other reactions which appeared give much larger widths for this level can be fitted using same parameters. second obtained about 10 Properties narrow 16·6 16·9 are also discussed.