Semiclassical approach to the line shapeThis paper was presented at the International Conference on Precision Physics of Simple Atomic Systems, held at École de Physique, les Houches, France, 30 May – 4 June, 2010.

Abstract

We extend the results of Bakalov et al. (Phys. Rev. Lett. 84, 2350 (2000)) on one-photon electric dipole transition line shift and broadening to the case of two-photon transitions. As an example, we consider the laser-induced transition in antiprotonic helium produced in a helium gas target. The transition is between antiprotonic helium states (n, l) = (33, 32) and (31, 30).