New analytic solutions of the collective Bohr Hamiltonian for a beta-soft, gamma-soft axial rotor

摘要

New analytic solutions of the quadrupole collective Bohr Hamiltonian are proposed, exploiting an approximate separation of the beta and gamma variables to describe gamma-soft prolate axial rotors. The model potential is a sum of two terms: a beta-dependent term taken either with a Coulomb-like or a Kratzer-like form, and a gamma-dependent term taken as a harmonic oscillator. In particular, it is possible to give a one-parameter paradigm for a beta-soft, gamma-soft axial rotor that can be applied, with considerable agreement, to the spectrum of U-234.