First experimental test of X(5) critical-point symmetry in the A~130 mass region: Low-spin states and the collective structure of 130 Ce

Excited, low-spin states in {sup 130}Ce are populated in the {beta}{sup +}/{epsilon} decay of {sup 130}Pr and studied through off-beam {gamma}-ray spectroscopy at the Yale moving tape collector. New coincidence data lead to the construction of a substantially revised level scheme. The low-lying states of {sup 130}Ce are compared with the predictions of the X(5) critical-point model and the X(5)-{beta}{sup 4} model, and the latter is found to give better agreement with the data in terms of energies. Discrepancies in the relative B(E2) values in {sup 130}Ce and the geometrical models suggest that the {gamma} degree of freedom may play an important role in this mass region.