Covariant Density Functional Theory: from Single-Particle to Collective Degrees of Freedom
- Anatoli Afanasjev, Mississippi State University
Tuesday, March 12, 11:00 AM - Theory Seminar
NSCL Seminar Room
Covariant density functional theory (CDFT) is well established theoretical tool for the description of nuclear systems. In this theory, the nucleus is described as a system of nucleons which interact by the exchange of different mesons. However, there were still a number of important topics which have not been either addressed or satisfactorily resolved within its framework prior to our recent works. In my talk, I will concentrate on three of them, namely, on single-particle degrees in spherical and deformed nuclei, their role and interplay with collective degrees of freedom in rotating nuclei, and fission barriers as an example of collective phenomenon.
The successes and limitations of the description of single-particle degrees of freedom in spherical and deformed nuclei within the CDFT will be discussed. Further improvement of the description of the energies of predominantly single-particle states and their wave functions requires beyond mean field methods built on CDFT which include particle-vibration coupling. The impact of particle vibration coupling on different physical observables such as the energies of predominantly single-particle states, the spin-orbit splittings, the energy splittings in pseudospin doublets will be illustrated in spherical nuclei ranging from light up to superheavy ones. The interplay of single-particle and collective degrees of freedom in rotating nuclei will also be discussed.
The fission barriers play an important role in the physics of heavy and superheavy nuclei; they are intimately connected with the existence and stability of superheavy nuclei. The CDFT has recently been confronted with experimental data on fission barriers in actinides and superheavy nuclei in a realistic manner. It is shown that the CDFT is able to describe fission barriers of actinides on a level of accuracy which is comparable with the best phenomenological macroscopic+microscopic approaches. The impact of pairing, triaxiality and octupole deformation on the properties of inner and outer fission barriers will be discussed.