Spectral Properties of Quasiparticle Interacting With Three-Mode Phonons, Taking Into Account Damping

Within the model of quasiparticle in two states interacting with three-mode polarization phonons at T=0K, the Fourier image of the Green's function is calculated considering non-phonon scattering mechanisms, which are taken into account by phenomenological damping. Accurate analytical expressions are obtained for the stationary energy spectrum of such system and the shape-function of its absorption band. It made possible to analyze the spectral properties of the system with and without the non-phonon damping.