Spin alignment in superdeformed Hg nuclei

One of the superdeformed rotational bands in Hg194 has transition energies (rotational frequencies) that are equal within about 0.1% to those of the (only known) band in Hg192. This excited (two-quasiparticle) band in Hg194 has an aligned spin of (1.00±0.04)Latin small letter h with stroke relative to the very similar band in Hg192, suggesting an interpretation in terms of aligned pseudo (intrinsic) spin. The implied pseudospin symmetry may be a clue as to why the rotational frequencies are so similar.