Anomalous behavior of the 2+ mixed-symmetry state in 94Zr

The low-spin structure of Zr-94 has been studied with the (n,n(')gamma) reaction, and branching ratios, lifetimes, multipolarities and spin assignments were determined. The 2(2)(+) state at 1671.4 keV has been identified as the lowest mixed-symmetry state in Zr-94. The 752.5-keV transition from this state to the 2(1)(+) level has a large B(M1) value of 0.33(5) mu(2)(N), and the B(E2) of the transition to the ground state has an unusually large value of 8(1) W.u. The M1 transition strength is in agreement with IBM-2 predictions in the U(5) vibrational limit, whereas the large B(E2;2(1,MS)(+)-> 0(1)(+)) value significantly exceeds the E2 strength predicted by the IBM-2. For the first time, the 2(1,MS)(+)-> 0(1)(+)E2 transition is observed to have a larger E2 transition strength than the 2(1)(+)-> 0(1)(+) decay.