Neutron-deficient N approximate to 126 nuclei produced in U-238 fragmentation: Population of high-spin states

The population of metastable states produced in relativistic-energy fragmentation of a U-238 beam has been measured. For states with high angular momentum, I=17h and I=21.5h, a higher population than expected has been observed, with the discrepancy increasing with angular momentum. By considering two sources for the angular momentum, related to single-particle and collective motions, a much improved description of the experimental results can be obtained. In addition, new results on the structure of Fr-208, Ra-211 and Ac-216 are reported.