Supersymmetric multiphonon structure

A multiphonon structure, which is known to exist in boson systems [e.g., the U(5) and O(6) limits of the interacting boson model], is shown to arise also in a mixed system of bosons and fermions. This is illustrated with the example of the Spin(6) limit of U(6|4) in which a j=3/2 fermion is coupled to an O(6) boson core. All states in the supersymmetric multiplet of U(6|4) are shown to be multiphonon states obtained by multiple action of a quadrupole operator. copyright 1996 The American Physical Society