Semiclassical approach to the line shape

TL;DR

This paper extends a semiclassical method to analyze line shapes, specifically for two-photon transitions, with an application to laser-induced transitions in antiprotonic helium, providing insights into line shifts and broadening effects.

Contribution

It introduces a semiclassical approach to two-photon transition line shapes, building upon previous one-photon results, and applies it to antiprotonic helium.

Findings

Extended semiclassical method for two-photon transitions.

Applied method to antiprotonic helium laser transition.

Provided quantitative analysis of line shift and broadening.

Abstract

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