Evolution of the β excitation in axially symmetric transitional nuclei -: art. no. 011304

The evolution of first excited 0(+) states in transitional nuclei of the Napproximate to90 region is correlated with the structure of the ground band. Iachello's X(5) solution for the Bohr-Hamiltonian for axially symmetric prolate nuclei is generalized to the transition path between X(5) and the rigid-rotor limit using infinite square-well potentials in the quadrupole deformation parameter beta with boundaries at beta(M)>beta(m)greater than or equal to0. Analytical solutions in terms of Bessel functions of first and second kind are derived and describe well the evolutionary trajectory of the studied 0(2)(+) states in this mass region.