next up previous
Next: Quantum Groups and Quantum Up: SELECTED MATHEMATICAL METHODS IN Previous: SELECTED MATHEMATICAL METHODS IN

Supersymmetry - Relation with the Shell-Model
and other Formalisms

It is an interesting and important aspect of some of the group-theory-based formalisms that they allow for a simultaneous, correct from the many body formulation point of view, description of fermions and bosons. In the simplest interpretation, the former are just the unpaired nucleons while the latter correspond to the coupled pairs of nucleons. A starting point of the formalism consists in employing a unitary supersymmetry U(n/m).

Using such a formalism it has been shown that the nuclei corresponding to the second half of the s-d shell are well described while those from the first half are not, important differences being predicted also by the shell model calculations. We would like to extend this type of studies and better approach the coupling mechanisms, in particular between the odd proton and the odd neutron. We should like to emphasize that the proton-neutron coupling, also in heavier rotating nuclei is an important current problem of the high-spin physics. Our study would bring an interesting possibility of confronting the results of various formalisms and conclude about a possible changing in the proton-neutron coupling schemes in function of nuclear mass, isospin and spin.

The supersymmetry concepts are also directly applicable in another physical context: that of the pseudo-spin symmetry and pseudo-spin transformation, both introduced originally many years ago and revisited recently in the context of nuclear superdeformation. We would like to examine a pseudo-spin transformation on the level of the Dirac equation together with the relations between the group of Lorentz/Poincaré and the group Osp(1/2). This research would allow to understand a deeper physical role of the pseudo-spin symmetry in both relativistic and non-relativistic formulations of the nuclear interaction problem.


next up previous
Next: Quantum Groups and Quantum Up: SELECTED MATHEMATICAL METHODS IN Previous: SELECTED MATHEMATICAL METHODS IN

2000-04-17