Direct observation of the inversion of flow

The sign of the mean transverse momentum of non-equilibrium light charged p articles was determined from the circular polarization of coincident gamma- rays emitted from residual nuclei for N-14-induced reactions on Sm-154 at i ncident energies, E/A = 35, 100 and 155 MeV. Results of the emitted alpha-p articles at mid-central collisions show the predicted transition from mean- field dominated dynamics at low energies to nucleon-nucleon collision domin ated dynamics at high energies. (C) 1999 Published by Elsevier Science B.V. All rights reserved.