Low-frequency structure in the depolarized spectrum of argon

Depolarized Rayleigh scattering spectra have been obtained in argon at five thermodynamic states. For the three spectra at liquid-like densities a relatively narrow component (half-width ≲10 cm−1) was discovered in the spectra. This component exhibits a roughly Lorentzian line shape and with it is associated about half of the total depolarized intensity. Its origin is the so-called ’’dipole-induced dipole’’ effect and it is assumed that it reflects the correlated motions of an atom and its near neighbors.