Antiproton capture by simple atoms and molecules

Antiprotonic atoms form in low-energy collisions between an antiproton and a normal atom or molecule. The fermion molecular dynamics (FMD) method enab les us to go beyond the atomic hydrogen target and study multielectron effe cts with helium and neon targets and molecular effects with hydrogen and de uterium targets. Multiple ionization and re-vibrational excitation are Foun d to greatly increase the maximum energy of capture, with the latter leadin g to a significant dependence on the projectile mass and target isotope. Th e kinetic energies of the ionized electrons are found to increase somewhat with the target nuclear charge.