Fragmentation properties of 6Li

The α+d and t+τ cluster structure of 6Li is described in a microscopic α+d cluster model through quantities that enter into the description of cluster fragmentation processes. The states of the separate clusters α, d, t and τ are described as superpositions of 0s Slater determinants belonging to different potential size parameters. The model state space of 6Li is a tensor product of the α and d cluster state spaces and the state space of zero-orbital-momentum relative motion, restricted by antisymmetrization. To describe both the 6Li and fragment states realistically, we constructed nucleon-nucleon forces optimized for the model state spaces used. The fragmentation properties calculated are the g.s. fragmentation (or reduced-width) amplitudes, their squared Fourier transforms, the corresponding potential overlaps, the spectroscopic factors Sαd, Stτand the αd asymptotic normalization constant Cαd. The forces constructed reproduce the energies and charge radii of 6Li as well as of the fragments excellently. The fragmentation properties predicted by them slightly differ from those calculated with some forces of common use provided the latter are modified so as to reproduce the α, d and 6Li energies. The fragmentation properties change moderately in comparison with simpler versions of the cluster model. The full model yields Sαd=0.93, Stτ=0.58 andCαd=3.3. The results are consistent with phenomenological estimates except for Cαd. The shape of our αd fragmentation amplitudes are in accord with α+p+n three-body calculations but our Sαdand Cαdare substantially larger. We attribute this discrepancy to the neglect of the Pauli effects in the usual three-body formula for the αd fragmentation amplitude. We give a formula which contains the necessary remedy.