Nuclear Drell-yan Process With High-energy Quark Energy Loss

In this paper, the nuclear effects on the bound nucleon structure functions and the models explaining nuclear effects are reviewed,such as x-rescaling model,quark cluster model and Q2-rescaling model. We also introducted the advantages and disadvantages for each model.But the greatest shortcoming of every model is that they depend on some unc phenomenal parameters. In 198,K.J.Eskola et.al.(EKS)suggested a set of nuclear parton distributions which are studied within the framwork of DGLAP evolution.The measurements of F2A /F2D in deep-inelastic l-A collisions,and Drell-Yan lepton cross sections measured in p - A collisions were used as constraints. The kinematical ranges are 10-6is the average path length of the incident quark in the nucleus A.Then,the p-ADrell-Yan cross section per nucleon considering energy loss is given byUsing this equation and the nuclear parton distribution studied only with lepton deep-inelastic scattering experimental data,we calculate and discuss the differential cross-section ratios versus x1, It is found that the results are in agreement with the experimental data .In addition,we also calculate the differential cross-section using the EKS nuclear parton distribution functions ,and find that without the energy loss ,the theoretical results agree very well with the experimental data. It is shown that the energy loss is another effect apart from the nuclear effect on the parton distribution in the deep-inelastic scattering process, and that the determination of nuclear parton distribution functions should not include Drell-Yan experimental data. In order to make a further study the energy loss effect, the prospects of using relatively low energy proton beams and several targets of differing A are presented.