A collective description of the unusually low ratio B-4/2 = B(E2; 4(1)(+) -> 2(1)(+))/B(E2; 2(1)(+) -> 0(1)(+))

The unusually low value of the ratio B-4/2 = B(E2; 4(1)(+) -> 2(1)(+))/B(E2; 2(1)(+) -> 0(1)(+)) along the yrast band is described in the interacting boson model-1. Two three-body interactions with SU(3) symmetry are additionally introduced into the usual Hamiltonian describing the transitional behaviors from the spherical vibration to the ellipsoidal rotation. In the SU(3) limit, the energy of the 4(+) state in the irrep (2N-8, 4) can be lower than the one of the 4(+) state in the irrep (2N, 0), which causes the anomaly. Copyright (C) EPLA, 2020