%0 Journal Article
%A Arbe, A.
%A Colmenero, J.
%A Alvarez, F.
%A Monkenbusch, M.
%A Richter, D.
%A Farago, B.
%A Frick, K. H.
%T Non-Gaussian nature of the alpha-relaxation of glass-forming polyisoprene
%J Physical review letters
%V 89
%@ 0031-9007
%C College Park, Md.
%I APS
%M PreJuSER-24202
%P 245701
%D 2002
%Z Record converted from VDB: 12.11.2012
%X We report quasielastic neutron scattering experiments exploring the alpha relaxation in polyisoprene over an unprecedented range in momentum transfer. Corroborating and validating earlier molecular dynamics simulations, the measurements reveal a crossover from a Gaussian regime of sublinear diffusion to a strongly non-Gaussian regime at short distances. We show that a consistent interpretation in terms of a distribution of finite jumps underlying the alpha process is possible. This model leads to a time-dependent non-Gaussian parameter exhibiting all features revealed so far from various simulations.
%K J (WoSType)
%F PUB:(DE-HGF)16
%9 Journal Article
%U <Go to ISI:>//WOS:000179484700027
%R 10.1103/PhysRevLett.89.245701
%U https://juser.fz-juelich.de/record/24202