Differences in the energy loss of protons and positive muons in solids

We evaluate the magnitude of the difference in the electronic energy loss o f positive muons and protons in solids in the low-energy range using both t he dielectric formalism and the non-linear transport cross-section (TCS) me thod. The effects of mass increase at low energies, showing stopping differ ences between 5% and 1% for velocities in the range 0.2 < <nu> < 1 a.u. We find that nuclear stopping effects must also be taken into account for a co nsistent analysis in the low-energy range. (C) 2001 Elsevier Science B.V. A ll rights reserved.