Excitation of atomic hydrogen by protons and multicharged ions

We have studied the excitation of an atomic hydrogen by H(+), Li(3+) and C(6+) ions in the range of intermediate and high impact velocities, upsilon = 1-7 au. The theoretical method is based on a one-centre close-coupling expansion of the time-dependent wavefunction, which includes a discretized representation of the ionization continuum. The calculated cross sections are in very good agreement with the available experimental measurements up to n = 6. In contrast. some discrepancies are observed for dipole-forbidden transitions when comparing with previous theoretical data. The results show the validity of the Janev-Presnyakov scaling law for both optically-allowed and forbidden excitation transitions.