Transport model description of the correlation between the energy loss and the variance of the charge or mass distributions in the heavy-ion deep inelastic reactions has been modified to include in the theory the effect of the degree of neutron-proton correlation in the particle exchanges. With the use of the revised theoretical expressions and considering the role played by the presence of correlations, the contradictions and discrepancies seen in the earlier analysis are removed. A better quantitative agreement with the experimental results is obtained by the present formalism. This brings out in an unambiguous way the dominant role of the nucleon exchange process in the energy loss mechanism.

NUCLEAR REACTIONS Heavy-ion reactions, energy loss, nucleon exchanges, neutron-proton correlations.

• Received 20 August 1981

DOI:https://doi.org/10.1103/PhysRevC.26.172