ELECTRONIC STOPPING POWER OF ELECTRON GASES FOR SLOW ANTIPARTICLES

The stopping power of slow antiparticles penetrating electron gases ar e evaluated within a scattering theory approach to the energy-loss pro blem. The required effective scattering potential is obtained from a s elf-consistent density-functional calculation. A relationship of the s topping power S proportional to \Z\(b) (b is in the range of 0.7-0.9) at low velocities is found, in contrast to the Z(2) dependence predict ed by the linear-response theory. The diffuse distribution of partial wave contributions of screening electrons in the case of antiparticles is quite different from that for normal particles and is thought to b e the main reason for the monotonic increment of the stopping power as a function of \Z\.