Strongly coupled bands as 'effectively' decoupled bands

We present experimental evidence which suggests that almost all the strongly coupled bands in the rare-earth region may also be treated as ''effectively'' decoupled bands. In contrast to the usual decoupled bands, the strongly coupled bands seem to arise from a system where a particle carrying an ''effective'' angular momentum j' is aligned to an even-even core having an ''effective'' rotational angular momentum R' which is not necessarily zero for the band head but may even have R'=2 or, 4 or, 6... etc. We attempt to explain these observations in a simple physical picture wherein Jsub(R), the projection of j, the particle angular momentum, on the rotation axis, is taken as the effectively aligned spin of the last particle. Preliminary results from schematic bandmixing calculations for hsub(9/2) and fsub(5/2) orbitals with the Fermi energy lying near the high K single particle levels indeed reveal the existence of ''effectively'' decoupled bands which seem to agree with this physical picture. (orig.)