Stopping characteristics for a slow antiproton

The energy loss, straggling, and dynamic width of slow antiprotons passing through an electron gas have been evaluated within a scattering-theory approach to the stopping-power problem. The required effective scattering potential is obtained from both a self-consistent density-functional calculation and a pseudo-linear-response treatment of the screening nonlinearities. The two methods give similar results. Comparison of the examined quantities with the case of protons reveals a marked difference in the metallic-density range