Effective two-body model for spectra of clusters of H 2, H 3, He 3, and He 4 with He 4, and H 2 - He 4 scattering

Four light-mass nuclei are considered by an effective two-body clusterization method: Li-7 as H-3 + He-4, Be-7 as He-3 + He-4, Be-8 as He-4 + He-4, and Li-6 as H-2 + He-4. The low-energy spectra of the first three are determined from single-channel Lippmann-Schwinger equations. For the last, two uncoupled sets of equations are considered: those involving the S-3(1) and those of the posited S-1(0) states of H-2. Low-energy elastic scattering cross sections are calculated from the same H-2 + He-4 Hamiltonian, for many angles and energies for which data are available. While some of these systems may be more fully described by many-body theories, this work establishes that a large amount of data may be explained by these two-body clusterizations.