par Arai, Koji;Descouvemont, Pierre ;Baye, Daniel Jean ;Catford, Wilton
Référence Physical review. C. Nuclear physics, 68, 1, page (13)
Publication Publié, 2003
Référence Physical review. C. Nuclear physics, 68, 1, page (13)
Publication Publié, 2003
Article révisé par les pairs
Résumé : | Resonance structures of excited states in [Formula Presented] and [Formula Presented] are studied by means of a microscopic multicluster model. The two-body scattering of [Formula Presented] or [Formula Presented] is solved by the microscopic R-matrix method where two-cluster wave functions of [Formula Presented] and [Formula Presented] are employed. These results are compared with the [Formula Presented] three-body complex scaling method to check the validity of neglecting three-body channels in the microscopic R-matrix method. The [Formula Presented] first excited state of [Formula Presented] which cannot be identified in the complex scaling method, is given as a [Formula Presented] virtual state with a purely imaginary complex momentum, and this resonance lies on the second Riemann sheet only for the [Formula Presented] channel. The [Formula Presented] resonance of the mirror nucleus [Formula Presented] 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 [Formula Presented] is discussed. © 2003 The American Physical Society. |