Wavenumber dependence of structural alpha relaxation in a molecular   liquid
  Structural alpha relaxation in liquid orthoterphenyl is studied by means of coherent neutron time-of-flight and backscattering spectroscopy over a large temperature range. Not only amplitude and relaxation time but also the spectral line shape show a significant variation with wavenumber. As expected from mode coupling theory, these variations are correlated with the static structure factor. Even far above the melting point, alpha relaxation remains non-exponential. 
A. Toelle (1), H. Schober, J. Wuttke, F. Fujara ((1) Institut of   physics, Dortmund, Germany)