THE QUADRUPOLE QUADRUPOLE INTERACTION AND THE INVERTED PAIRING

We present evidence that excitations induced by the quadrupole-quadrup ole interaction are equivalent to an inverted surface-delta interactio n whose largest multipole-pairing component is attractive and has maxi mum spin. This technical recognition led one to isolate the system's i ntrinsic energies from the rest in the laboratory frame, trace the ori gin of the recently introduced optimum pair description of rotation an d derive approximate but accurate analytical expressions of various ba nd energies.