Electron–proton scattering in a laser field

A new theoretical ansatz for investigating the scattering dynamics of atoms in strong visible and UV laser fields is presented. The time dependence for the interaction with circularly polarized light is treated in a rotating coordinate system, the interaction is made explicitly short range by the space-translation transformation, and the distortion of the atom by the field is included efficiently through the introduction of spheroidal coordinates. T-matrix elements for electron–proton scattering accompanied by multiphoton processes are given, and the extensions necessary to calculate above-threshold ionization with photoelectron energy distributions are discussed.