Angular Momentum Population in Projectile Fragmentation

Abstract. Isomeric states in neutron-deficient nuclei around A≈190 have been identified following the projectile fragmentation of a relativistic energy 238U beam. The deduced isomeric ratios are compared with a model based on the abrasion-ablation description. The experimental isomeric ratios are lower by a factor of ≈2 than the calculated ones assuming the ‘sharp cutoff’ approximation. The observation of the previously reported isomeric I π=43/2− state in 215Ra represents the current record for the highest discrete spin state observed following a projectile fragmentation reaction.