High frequency sound waves in vitreous silica
  We report a molecular dynamics simulation study of the sound waves in vitreous silica in the mesoscopic exchanged momentum range. The calculated dynamical structure factors are in quantitative agreement with recent experimental inelastic neutron and x-ray scattering data. The analysis of the longitudinal and transverse current spectra allows to discriminate between opposite interpretations of the existing experimental data in favour of the propagating nature of the high frequency sound waves. 
R. Dell'Anna (L'Aquila), G. Ruocco (L'Aquila), M. Sampoli (Firenze),   G. Viliani (Trento)