A NOTE ON QUASI-ELASTIC NEUTRON-SCATTERING

We present a theorem that in coherent quasielastic neutron scattering on a confined and limited system of identical particles only the configuration-configuration correlations have to be examined without any hindsight on the distribution of the particles inside the configuration. This constitutes a strong simplification with respect to the problem where all particle-particle correlations would have to be accounted for. The method is illustrated on an example of correlated hopping on a piece of an octagonal quasiperiodic tiling. With some modifications the method can also be used for incoherent scattering. A further simplification of the calculations both for coherent and incoherent scattering functions is obtained by introducing a new matrix notation that allows fully for the symmetry properties of the problem.