Low-velocity antiproton stopping power

The stopping power of antiprotons moving at low velocities through a uniform electron gas is calculated by making use of the momentum-transfer cross section. The static screening potential required is obtained from a self-consistent nonlinear screening calculation within density-functional theory. Our results indicate that the corrections beyond linear-response theory are particularly significant for negatively charged particles. We obtain, for example, a ratio of about two for the proton and antiproton stopping powers throughout the metallic density range.