Low-energy electron-argon scattering in a low-frequency laser field

We have used several non-perturbative Roquet methods to calculate the differential and total cross sections for electron scattering from argon in a CO2 laser field. One method utilizes the mixed-gauge R-matrix technique to calculate the scattering cross section. A diabatic approximation adopted from molecular applications is also applied to this low-frequency limit. Results are compared with the well known Kroll-Watson approximation. We find that all three theoretical treatments agree well with each other but do not agree with some experimental results. Possible explanations for the discrepancy between the calculations and experiments are examined.