1/N expansion formalism for high-spin states

The 1/$N$ expansion solutions for the interacting boson model are extended to higher orders using computer algebra. The analytic results are compared with those obtained from an exact diagonalization of the Hamiltonian and are shown to be very accurate. The extended formulas for level energies and E2 transitions will be useful in the analysis of high-spin states in both normal and superdeformed nuclei.