Spectral line shape. I. Kinetic equation for arbitrary frequency detunings

Abstract

A theoretical formulation of the problem of the spectral line shape is presented using the superoperator technique. Conventional approximations, such as the long wave approximation, the binary approximation and the classical motion of molecular centers of mass, are employed. The kinetic equation for the line profile from resonance to the far wings is derived. Its main feature is that the terms prevailing at small or large frequency detunings are separated in the equation itself.