title: Evaluation of x-ray Brillouin scattering data.
abstract: Making use of the classical second-moment sum rule, it is possible to convert a series of constant-Q x-ray Brillouin scattering scans (Q momentum transfer) into a series of constant frequency scans over the measured Q range. The method is applied to literature results for the longitudinal phonon dispersion in several glass formers. The constant frequency scans are well fitted in terms of a Q-independent phonon damping depending exclusively on the frequency, in agreement with two recent theories of the boson peak. The method allows us to link the x-ray Brillouin scattering to the diffuse Umklapp scattering from the boson peak vibrations at higher momentum transfer on an absolute intensity scale.
authors.affiliation: Jülich Center for Neutron Science, Forschungszentrum Jülich Postfach 1913, D-52425 Jülich, Federal Republic of Germany.
authors.forename: U
authors.initials: U
authors.lastname: Buchenau