Coupled channels analysis of 8He+4He scattering and resonant behaviour

Previously measured elastic scattering and two-neutron transfer angular distributions for 8He scattered from a 4He target [Phys Lett. B 75, 58-62, 2017] are analysed using the coupled reaction channels (CRC) formalism and the effect of 1, 2 and 4-neutron transfers on both the elastic scattering and 6He + 6He channels is examined. The CRC calculations find that 1n and 2n transfers are the dominant processes in the production of 6He while the influence on the elastic scattering of 4n transfer between the 4He cores is small. Calculated excitation functions based on fits to both data sets suggest resonant-like behaviour centred at 12Be excitation energies of about 13 MeV and 14-16 MeV, both associated with the L=2 and 4 partial waves and consistent with molecular structures in the intermediate 12Be system.