Detailed spectroscopy of 110Cd: Evidence for weak mixing and the emergence of γ-soft behavior

A study of the beta(+)-electron capture decay of In-110 into levels of Cd-110 is combined with a reanalysis of data from a previous study of Cd-110 with the (n, n'gamma) reaction with monoenergetic neutrons. The gamma gamma coincidences from the In-110 decay leads to many new assignments of gamma rays observed in the (n, n'gamma) reaction, permitting the observation of weak low-energy transitions, and setting stringent upper limits on unobserved decay branches. The uncertainties on many of the lifetimes from the (n, n'gamma) reaction are significantly reduced, and limits are established for the lifetimes of levels too long for a direct measurement. The absence of enhanced transitions between the previously assigned phonon states and the deformed intruder states strongly suggests that mixing between the configurations is generally weak, refuting the strong-mixing scenario as an explanation of the decay pattern of the excited 0(+) states in Cd-110. The decay pattern of the nonintruder states is suggestive of a gamma-soft rotor, or O(6) nucleus, rather than a vibrational, or U(5), pattern. The existence of a four-particle-six-hole proton excitation in Cd-110 is also suggested.