Recent Progress in Quantum Monte Carlo Calculations of Nuclear Structure and Reactions

We describe recent progress in Quantum Monte Carlo calculations of nuclear structure and reactions. Significant advances have been made recently in understanding the nuclear Hamiltonian, including realistic two- and three-nucleon interactions. We describe recent progress in solving the nuclear Hamiltonian for two important long-standing problems in nuclear theory: (1) low-energy scattering in n-4He and the spin-orbit splitting obtained with microscopic Hamiltonians, and (2) the pairing gap in low-density neutron matter. Accurate calculations of both quantities are fundamental in understanding nuclei from the underlying microscopic Hamiltonian.