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

Abstract

Excited, low-spin states in Ce130 are populated in the ?+/? decay of Pr130 and studied through off-beam ?-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 Ce130 are compared with the predictions of the X(5) critical-point model and the X(5)-?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 Ce130 and the geometrical models suggest that the ? degree of freedom may play an important role in this mass region. � 2008 The American Physical Society. Show more