Collective excited states of even-even nuclei with quadrupole and octupole deformations

Full text: Analytical expression for energy levels of excited states of the axial-symmetry nuclei with quadrupole (β2) and octupole (β3) deformations for exponential type potential energy for the surface longitudinal oscillations are obtained in the following form: V=Cσ02/2 exp[-(σ - σ02)/σ02], Where: σ2=(B2-β22/B2+B3) + (B2β33/B2+B3), B2 and B3-mass parameters for quadrupole and octupole deformations, C-rigid parameter for surface oscillations, and σ0-deformation parameter in the ground state. Energy levels of excited states with positive and negative parity defined by two parameters: soft parameter relative surface oscillations μ(0≤μ≤1) and εν energy parameter, which is the eigenvalue of Schrodinger equation in polar coordinates, ν=0,1,2,.. The obtained theoretical results show, that the proposed model satisfactorily describes experimental values of energy levels of positive and negative parity excited states of even-even nuclei 158,160Dy, 232,234,236,238U, including high spin states. It is also discovered that the exponential type potential energy of the surface oscillations satisfactorily describes only energy levels of rigid nuclei, i.e. when μ≤1/3. (authors)