Relaxation of the mass-asymmetry degree of freedom in heavy-ion reactions.

The /sup 58/Ni+ /sup 165/Ho reaction has been studied at 5.9 and 6.5 MeV per nucleon (reverse kinematics). Coincident reaction fragments were detected with two position-sensitive parallel plate avalanche detectors. Correlations between energy, mass, and angle show that a small fraction of the events have fully relaxed kinetic energies, masses intermediate between those of the projectile (target) and symmetric fragmentation, and angular distributions with a marked forward-backward asymmetry.