Mass and charge distributions with correlated exchange

The dependence of the inclusive variances sigmasub(A)2, sigmasub(Z)2 and sigmasub(N)2 in nuclear collisions is investigated as a function of the correlation coefficient rho for isospin correlated nucleon exchange on the dinuclear potential energy surface (PES). Variances for neutron-proton cluster exchange (single step process with zero net momentum between the constituents) are also evaluated. This analysis is helpful to understand the nature of the exchange mechanism. There exist a few experimental data which are at variance with either uncorrelated neutron-proton exchange or with isospin correlated exchange. An explanation of this data may possibly lie in coexisting neutron-proton cluster exchange. (orig.)