Hydrogen excitation by antiproton and multicharged-ion impact

Electron excitation by multicharged ions colliding with hydrogen targets is calculated with the prior eikonal impulse approximation. Cross sections for excitation to n=2 and 3 by impact of antiprotons (p), protons (p), He 2+ , Be 4+ , and O 6+ , are reported as well as the density matrix elements, multipole expansion parameters, dipole moments and perihelion velocities. The theory gives a good account of the available experiments and compares well with other sophisticated theoretical methods in the intermediate energy range (25>or=E/Z P >or=200 keV).