Abstract
The magnetic dipole strength in the energy region of the spin-flip resonance is investigated in and using quasimonoenergetic and linearly polarized -ray beams at the High-Intensity -Ray Source facility in Durham, North Carolina, USA. Absorption cross sections were deduced for the magnetic and electric and dipole strength distributions separately for various intervals of excitation energy, including the strength of states in the unresolved quasicontinuum. The magnetic dipole strength distributions show structures resembling a resonance in the spin-flip region around an excitation energy of 8 MeV. The electric dipole strength distributions obtained from the present experiments are in agreement with the ones deduced from an earlier experiment using broad-band bremsstrahlung instead of a quasimonoenergetic beam. The experimental magnetic and electric dipole strength distributions are compared with phenomenological approximations and with predictions of a quasiparticle random phase approximation in a deformed basis.
- Received 13 August 2014
- Revised 25 September 2014
DOI:https://doi.org/10.1103/PhysRevC.90.054310
©2014 American Physical Society