Abstract
The (p,nSc reaction was studied at 134 MeV. Neutron energy spectra were measured by the time-of-flight technique with resolutions of 220 keV at angles from 0° to 41° and 415 keV out to 62°. The ,,, band of states based on the (,) 1p1h structure was observed at low excitation energies, in good agreement with known analog states in and . The shapes of the cross-section and analyzing-power angular distributions are in good agreement with distorted-wave impulse-approximation calculations using simple 1p1h (Tamm-Dancoff approximation) shell-model wave functions. A relatively strong transition to a state at =2.3 MeV with L=3 is identified tentatively as a state with the predominant 1p1h structure (1,2).
The excitation of the (T=1) (,) stretched state is observed near =7 MeV, fragmented over approximately 3 MeV. The normalization factor required to make a distorted-wave impulse-approximation calculation agree in magnitude with the excitation is 0.35, which is larger than the normalization factor for this excitation in mass 28, analyzed in a similar manner. The L=1 giant resonance is observed to be centered near =10 MeV with a width (full width at half maximum) of about 5 MeV, and a distorted-wave impulse-approximation normalization factor of 0.16. Two excitations are observed at =2.7 and 4.3 MeV which indicate directly the presence of ground-state correlations in the target. The fact that the analog of the higher excitation is not seen in inelastic electron scattering indicates strong interference between spin and orbital current contributions. The effect of ground-state correlations on the 1p1h wave functions was investigated by performing calculations which allowed multiparticle-multihole correlations in the and orbitals. The distorted-wave impulse-approximation normalization factors obtained with these wave functions were found to increase by a factor of about 2 relative to those obtained with assumed to be a closed core.
- Received 11 February 1986
DOI:https://doi.org/10.1103/PhysRevC.34.80
©1986 American Physical Society