Speaker
Description
The research project presented in this contribution combines the well established achievements elaborated already during the preceding century and the more recent ones mainly related to the exotic nuclear shape symmetries. It focuses on the realistic applications of the phenomenological nuclear mean field theory in low energy nuclear structure phenomena. This involved in particular the physics of nuclear shapes, including shape evolution and competition, symmetries and spontaneous symmetry breaking, nuclear rotation including high spin physics as well as rotational band properties involving band crossings, back-bending, angular momentum alignment, staggering phenomena including exotic identical band manifestations as one of the powerful structure identification tools. The term universal refers to the fact that Hamiltonian in question operates with 8 parameters optimized for all nuclei of the Nuclear Mass Table and employed without modifications.
Nuclear super-deformation at high spins played a distinct role in the discussed research. Prediction of the whole super-deformed island in Rare Earth nuclei preceded by one year its first experimental identification in $^{152}$Dy by Twin and collaborators. From perspective, combining theory and experimental efforts allowed discovering powerful symmetries known today as pseudo-spin and pseudo-SU(3) symmetries. The latter contributed to prediction of even stronger deformation effects: nuclear hyper-deformation.
The mentioned theory efforts were regularly transmitted to the US community thanks to regular Gordon (GRS) conference invitations, cf., in 1987, 1991, 1993, followed in the years 2000. As one of the consequences, the discussed theory impact was brought into one of the most important experimental nuclear physics projects of those times: multi-detector system GAMMASPHERE. Already at the proposal writing level the search of super-, and hyper-deformations was strongly emphasized$^1$.
Another branch of investments profiting from advances in the nuclear mean-field was focused on the very special molecular symmetries in nuclei, tetrahedral and octahedral ones -- also referred to as high-rank symmetries. In terms of the mean-field physics both of these symmetries manifest 4-dimensional irreducible representations; as a consequence certain nucleon levels are 4-fold degenerate (in contrast to 2-fold Kramers degeneracy).
Numerous encouraging consequences of these symmetries as well as the world first identifications will be presented as the second part.
$^1)$ The AI reports dated 2026 -- about the vivid discussions of those times and reactions from the GRS community -- mention explicitly terms such as Dudek plots and `famous Dudek'ism about tetrahedral nuclei'. With permission of organizers this AI words will be explained in September...