The evolution of the octupole excitations with mass, charge number and the angular momentum
Final Report Abstract
Among the fundamental characteristics of the atomic nucleus there is its shape. Nuclear shape determines the spectra of the low-lying nuclear excitations. The most important multipole deformations of a nuclear shape are the quadrupole and octupole deformations. Quadrupole deformation is reflection symmetric. ln contrast, octupole deformation is reflection asymmetric. Nuclear properties related to quadrupole deformation are well investigated. Those related to octupole deformation are less known. Concerning quadrupole deformation, several nuclei in the rare earth, actinide region and those with Z~100 are known as having rigid quadrupole deformation. However, we do not know how rigid octupole deformation is in nuclei in which octupole collective motion is important. Recently very interesting experimental data on the evolution of nuclear properties related to octupole excitations with the increase of the angular momentum have been obtained. The nuclear structure phenomena related to the manifestation of the octupole collective motion have been investigated in the framework of this project. Analyzing experimental data we have shown that with an increase of the angular momentum the second order phase transition from the octupole-nondeformed to the octupole-deformed shape takes place. lt was shown further that anharmonicity in the octupole motion plays an important role and a theoretical technique has been developed to describe the effects of anharmonicity. Analyzing the properties of the alternating parity rotational bands at high angular momenta we found a universality ih the angular momentum dependence of the octupole deformation. The results of the analysis reveal a possibility to predict the excitation energies of the states with high angular momentum. lt can be done by a comparison of the experimental data for the low angular momenta part of its spectra with the spectra of some other nuclei having longer alternating parity bands.
Publications
- Phys.Rev. C 86, 024319 (2012)
R.V. Jolos, P. von Brentano, and J. Jolie
- J.Phys. Conf. Ser., 533, 012039 (2013)
R.V. Jolos
- Phys.Rev. C 88, 034306 (2013)
R.V. Jolos, P. von Brentano, and R.F. Casten
- Phys.Rev. C 92, 044318 (2015)
R.V. Jolos, P. von Brentano
(See online at https://doi.org/10.1103/PhysRevC.92.044318)
