Abstract
Resonance structures of excited states in and are studied by means of a microscopic multicluster model. The two-body scattering of or is solved by the microscopic R-matrix method where two-cluster wave functions of and are employed. These results are compared with the three-body complex scaling method to check the validity of neglecting three-body channels in the microscopic R-matrix method. The first excited state of which cannot be identified in the complex scaling method, is given as a virtual state with a purely imaginary complex momentum, and this resonance lies on the second Riemann sheet only for the channel. The resonance of the mirror nucleus has a very large width, and its excitation energy as obtained from the analytic continuation of the S matrix to the complex energies shows a normal Thomas-Ehrman shift. The dimensionless reduced widths and the reduced width amplitudes are calculated for low-lying resonances, and the cluster structure of these states in is discussed.
- Received 4 February 2003
DOI:https://doi.org/10.1103/PhysRevC.68.014310
©2003 American Physical Society