Fragment mass dependence of transverse momentum transfer: Mean-Field vs. NN collision

The directed transverse momentum, , of light particles (p,d,hor-ellipsis) is produced through the interplay of the nuclear mean field and nucleon-nucleon collisions. contains a random component and a component due to the collective momentum transfer. For intermediate and heavy mass fragments, the random component is expected to diminish, whereas the collective momentum transfer increases in importance. The authors intend to corroborate this by using the optical model of transverse momentum transfer for the systems Ar, Nb, La and Au at GeV per nucleon energies and present calculations for Pperpendicular (Bounce)/AF, where Pperpendicular (Bounce) is the extra component needed to fit the transverse momentum widths of fragments. The role of the nuclear mean field in determining the fragment momentum widths will be discussed