  We describe a path-integral ground-state quantum Monte Carlo method for light
nuclei in continuous space. We show how to efficiently update and sample the
paths with spin-isospin dependent and spin-orbit interactions. We apply the
method to the triton and alpha particle using both local chiral interactions
with next-to-next-to-leading-order %(N$^2$LO) and the Argonne interactions. For
operators, like the total energy, that commute with the Hamiltonian, our
results agree with Green's function Monte Carlo and auxiliary field diffusion
Monte Carlo calculations. For operators that do not commute with the
Hamiltonian and for Euclidean response functions, the path-integral formulation
allows straightforward calculation without forward walking or the increased
variance typical of diffusion methods. We demonstrate this by calculating
density distributions, root mean square radii, and Euclidean response functions
for single-nucleon couplings.
