Semiclassical approach to the line shape

We extend the results of Bakalov D., B.Jeziorski, T.Korona, K.Szalewicz, E.Tchoukova, Phys. Rev. Lett. {\bf 84} (2000) 2350, 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 helium gas target. The transition is between antiprotonic helium states $(n,l)=(33,32)$ and $(31,30)$. PACS 32.70.Jz, 34.20.Gj, 36.10.-k