Microscopic description of low-lying M1 excitations in odd-mass actinide nuclei
Abstract
A restoration method of a broken symmetry which allows self-consistent determination of the separable effective restoration forces is now adapted to odd-mass nuclei in order to restore violated rotational invariance (RI-) of the Quasiparticle Phonon Nuclear Model (QPNM) Hamiltonian. Because of the self-consistency of the method, these effective forces contain no arbitrary parameters. Within RI-QPNM, the properties of the low-lying magnetic dipole excitations in odd-mass deformed 229-233Th and 233-239U nuclei have been investigated for the first time. It has been shown that computed fragmentation of the M1 strengths below 4 MeV in these nuclei is much stronger than that in neighboring doubly even 228-232Th and 232-238U nuclei. For 235U the summed M1 strength in the energy range 1.5-2.8 MeV is in agreement with the relevant experimental data where the missing strength was extracted by means of a fluctuation analysis.
- Publication:
-
Nuclear Physics A
- Pub Date:
- January 2017
- DOI:
- 10.1016/j.nuclphysa.2016.07.004
- Bibcode:
- 2017NuPhA.957...33T
- Keywords:
-
- Actinide;
- Odd-mass;
- M1 excitations;
- Scissors mode;
- Rotational invariance;
- QPNM