Abstract
The αCa elastic scattering cross sections in the energy range from 29.0 to 61.0 MeV are shown to be well reproduced by the resonating-group method by introducing a phenomenological imaginary potential. The local potential equivalent to the nonlocal potential of the resonating-group method is found to be very close to the optical potential of Delbar et al. which fits the scattering data well in a wide energy range. Since the optical potential of Delbar et al. is the so-called unique optical potential which is free from the discrete ambiguity, this result means that the resonating-group method is powerful and reliable for the study of the internucleus interaction. By calculating the bound and quasibound level spectra by the same αCa resonating-group method, it is found that the lowest positive parity rotational band is located near the observed ground rotational band of . In addition, when we use other effective two-nucleon forces so as to locate the calculated lowest state near the observed excited state with the excitation energy 8.54 or 11.2 MeV, which has large α strength, the fitting of the elastic scattering data by the resonating-group method is found to be very bad. These results force us to regard that the structure of the ground band as containing a large amount of αCa clustering component. However our present resonating-group method predicts the appearance of the negative parity rotational band with its bandhead state below the excitation energy 10 MeV although there have been reported no such experimental indications at all of this.
- Received 2 May 1988
DOI:https://doi.org/10.1103/PhysRevC.38.2063
©1988 American Physical Society