Satellite structure in the 2pσ molecular orbital transitions in slow heavy ion collisions

The binding energy of the 2pσ molecular orbital formed transiently in a slow heavy ion collision shows a flat minimum at a large internuclear distance. Electronic transitions in this minimum provide a satellite structure in the 2pσ X-ray continuum, which was not found in the original search. New measurements show that the satellite is only evident at very small collision velocities, since the collision broadening is much larger for asymmetric collision systems than the theory predicts. The present theory of collision broadening takes into account only the linear term of the change in transition energy dE/dR which may not be appropriate in cases where the second term d²E/dR² is likely to be dominant.