Quantum Monte Carlo Calculations of Nucleon-Nucleus Scattering

We report recent quantum Monte Carlo (variational and Green's function) calculations of elastic nucleon-nucleus scattering. We are adding the cases of proton-$^{4}$He, neutron-$^{3}$H and proton-$^{3}$He scattering to a previous GFMC study of neutron-$^{4}$He scattering [1]. To do this requires generalizing our methods to include long-range Coulomb forces and to treat coupled channels. The two four-body cases can be compared to other accurate four-body calculational methods such as the AGS equations and hyperspherical harmonic expansions. We will present results for the Argonne v$_{18}$ interaction alone and with Urbana and Illinois three-nucleon potentials. \\[4pt] [1] K.M. Nollett, S. C. Pieper, R.B. Wiringa, J. Carlson, and G.M. Hale, Phys. Rev. Lett. 99, 022502 (2007)