Friction and diffusion coefficients in coordinate in nonequilibrium nuclear processes

The influence of different sets of friction and diffusion coefficients on t he dynamics of a nuclear system is investigated. Taking as an example a din uclear system we show in a "classic" investigation that with zero diffusion in the coordinate, the uncertainty relation can be violated during short i nitial times. Sets of diffusion coefficients are found for which the "class ic" and quantum diffusion equations give close physical results. The tunnel ing through an energy barrier is sensitively influenced by the friction and diffusion coefficients in coordinate in the diffusion equation. (C) 1999 E lsevier Science B.V.