ΔI=4 fifurcation without explicit fourfold symmetry

We demonstrate that ΔI=4 bifurcation can arise from the projected shell model without introducing explicitly either a Y44 deformation or an I4 term in the Hamiltonian. If band mixing through the usual two-body Hamiltonian is dominated by a single two-band mixture near the yrast line, a clear staggering can appear. Detailed investigation shows that this staggering is associated with interference effects in the rotation from intrinsic to laboratory coordinate systems. copyright 1995 The American Physical Society