Spherical vibrator model with an energy increasing stiffness

A new parameter free collective solution is proposed by inducing a linear energy dependence in the five-dimensional harmonic oscillator potential of the Bohr Hamiltonian and taking the asymptotic limit of the slope. The model preserves the degeneracy features of the U(5)U(5) dynamical symmetry but with an expanded energy spectrum and with damped E2 transition probabilities. The 116Cd nucleus is presented as an experimental realization of the model.