K-HINDRANCE IN PRIMARY GAMMA-DECAY AFTER THERMAL AND AVERAGE RESONANCE NEUTRON-CAPTURE

The intensities of primary gamma-ray transitions following thermal and average resonance neutron capture have been found to display a depend ence on the final-state K quantum number. The apparent K-hindrance eff ect is significantly stronger in the thermal than in the average reson ance case. After thermal neutron capture, the intensity distributions indicate that the ''K-allowed'' transitions are associated with a high er number of degrees of freedom than the ''K-forbidden'' transitions. Possible explanations for the observed phenomena are discussed.