Alpha and 8Be cluster amplitudes and core excitations in s-d shell nuclei

Abstract

SU(3) and SU(4) recoupling are used to develop techniques for the calculation of norm and overlap matrix elements for properly antisymmetrized cluster wave functions. These techniques are illustrated in detail by the calculation of [alpha] and 8Be cluster amplitudes for states of a few h[omega] excitation in s-d shell nuclei. These extend earlier SU(3) strong coupling results for states of highest intrinsic deformation to all values of ([lambda][mu]), making it possible to calculate [alpha]-amplitudes for SU(3) weak and intermediate coupling wave functions. The extreme SU(3) weak and strong coupling limits for a-amplitudes are compared for states of 1 h[omega] excitation in light s-d shell nuclei. A general formulation is given for the calculation of spectroscopic amplitudes for the transfer of 8Be clusters in (12C, [alpha]) or (14N, 6Li) reactions on nuclei for which SU(3) and SU(4) are meaningful symmetries. The method is illustrated by predictions of 8Be amplitudes to the prominent rotational bands in 20Ne.