Abstract
We propose a method of spin-parity assignments in decay spectroscopy. Its feasibility was tested for the -delayed neutron decay of spin-polarized The -decay asymmetries were measured in coincidence with the delayed neutrons, and the values were evaluated for five allowed transitions leading to the excited states in 4.220, 4.657, 5.866, and 6.426 MeV). The spin parities of the former three states were uniquely assigned as and respectively. These assignments are consistent with the previous assignments. Because of insufficient statistics for the 5.866-MeV state an incorrect assignment could not be excluded within the deviation. The spin-parity of the 6.417-MeV state is suggested to be The peak analysis with detector response in the neutron time of flight spectra enabled precise determinations of the level energies and widths. The level widths were determined for the first time. The present method is also applicable for -delayed proton, and decays, and it can be a powerful tool for spectroscopic studies of nuclei far from the stability.
- Received 1 February 2002
DOI:https://doi.org/10.1103/PhysRevC.67.014306
©2003 American Physical Society