Collinear study of protonium formation in collisions of antiprotons with hydrogen molecular ions

Applicability of the Born-Oppenheimer adiabatic approximation is examined for the protonium formation process (p) over bar + H-2(+) --> (p) over barp + H. For this purpose, a collinear configuration is assumed for the three nuclei, and a calculation using a quantum-classical hybrid (semiclassical) method is carried out. The collinear study suggests that the molecular target is much more efficient for the production of the protonium atom than the target of atomic hydrogen. (C) 2003 Elsevier B.V. All rights reserved.