Barkas effect for antiproton stopping in H2

Phys Rev Lett. 2002 Oct 28;89(18):183201. doi: 10.1103/PhysRevLett.89.183201. Epub 2002 Oct 10.

Abstract

We report the stopping power of molecular hydrogen for antiprotons of kinetic energy above the maximum (approximately 100 keV) with the purpose of comparing with the proton one. Our result is consistent with a positive difference in antiproton-proton stopping powers above approximately 250 keV and with a maximum difference between the stopping powers of 21%+/-3% at around 600 keV.