Abstract
The M1 strength in a number of γ → g transitions in
168Er have been determined from high-precision L-subshell conversion electron intensity measurements. The results are combined with earlier data for transitions within the γ-band and compared with the predictions of an IBA-2 calculation. It is shown that a satisfactory description of both E2 and M1 properties can be obtained with the appropriate degree of
F-spin symmetry breaking in the hamiltonian, which in turn relates to the degree of neutron-proton symmetry in the collective wavefunction.