On K-factor's non-constancy for the Drell-Yan process in carbon-carbon nuclear collision

The double Q(2)-rescaling model is used to compute the change of K-factor w ith x(A2) when the nucleus carbon-nucleus carbon collision occurs at differ ent values of x(A1), where x are momentum fraction variables. In the calcul ation, the contributions of annihilations and Compton scattering have been considered for the Drell-Yan process. The calculated results show that the plots of K-factor versus x(A2) are very different for different values of x (A1). They are also compared with experimental data, which provides a test to the model of nuclear effect and the QCD theory itself.