Resonances and collisional properties of neutron-rich helium isotopes in the adiabatic hyperspherical representation

The goal of this work is to treat few-body nuclear systems using the adiabatic hyperspherical representation, to test an alternative approach to treat both bound and continuum states and compare the results to other techniques often used in nuclear calculations. This method is utilized to solve the N-body Schr & ouml;dinger equation for the three- and four-body systems, treating both 6He and 7He nuclei. A simplified central potential model for the 4He -n interaction is used in conjunction with a spin-dependent three-body interaction to reproduce 6He bound-state and resonance properties as well as properties for the 8He nucleus in its ground state. With this Hamiltonian, bound and scattering states for both 6He and 7He nuclei are computed. For the 6He system, the electric quadrupole transition between the 0+ and 2+ state is investigated. For the 7He system, 6He +n elastic scattering is investigated along with the four-body recombination process 4He +n + n + n -* 6He +n and breakup process 6He + n -* 4He + n + n + n. An application of the adiabatic hyperspherical representation to a five-body description of 8He is also presented with the prospects of studying four neutrons in the scattering continuum that interact with a core nucleus.