Kinematic Resonances in Crystalline Xenon

A resolvent formalism is applied to the calculation of optical absorption in solid Xe. For realistic models of the energy bands and the electron-hole interaction, the spectrum contains narrow resonances (poles of the $t$ matrix) in the continuum. Although the form of these kinematic resonances is strongly dependent on the truncation radius of the interaction, the results support Phillips's explanation of resonant structure in the optical data on Xe.