Investigation of quadrupole deformation of nucleus and its surface dynamic vibrations

Abstract
The new complete database - Chart of nuclear quadrupole deformations - was developed using various sources of related information. Using this Chart the system comparative analysis of quadrupole deformation parameters β₂ obtained by two different methods was carried out for many nuclei. The clear systematical disagreements of β₂ parameters obtained from nuclear quadrupole moments Q ("Q-type" data) and from reduced transition probability B(E2) ↑ for 0⁺ → transitions ("B-type" data) were revealed. It was found out that all nuclides investigated are clearly separated into two groups. For all isotopes of "group 1" nuclei good agreement was observed for data of both types. For all isotopes of "group 2" nuclei "B-type" β₂ data values are systematically (in many cases significantly) larger than "Q-type" ones. In cases of only few exceptions disagreement for some isotopes are combined with agreements for others. It was shown that two types data difference could be explained in the frame of assumption about the not negligible role of dynamic vibrations of nucleus surface, by other words, about dependence of quadrupole deformation parameter β₂ values on surface vibrations of nucleus in ground state. From this point of view "Q-type" β₂ values do not take into account nucleus surface vibration, but "B-type" β₂ values do that. Therefore "B-type" data reflect not only static nuclear deformation (deviation of nucleus shape from spherical), but dynamic deformation also.