Low-energy alpha+ He-6 elastic scattering with the resonating-group method

The alpha + He-6 elastic scattering is investigated within a microscopic mu lticluster model, involving a realistic description of the He-6 halo nucleu s. Phase shifts and elastic-scattering cross sections are calculated up to E-c.m. = 15 MeV with two variants of the resonating-group method. The model gives rise to 1(-) and 3(-) molecular states near E-c.m. = 0.5 MeV and E-c .m. = 3.7 MeV, respectively. We suggest that the broad 3(-) resonance shoul d be observable by comparing elastic cross sections at different energies. We also evaluate the order of magnitude of the He-6 breakup cross section. [S0556-2813(99)03902-3].