能量损失效应引起的核Drell-Yan微分截面比的压低(英文)

Suppression of Nuclear Drell-Yan Ratios Due to Energy Loss Effect

核环境中夸克的能量损失可以通过高能核Drell-Yan过程的核依赖进行测量．利用文献中给出的夸克能量损失公式和从轻子-原子核深度非弹性散射实验数据得到的束缚核子中的部分子分布函数,计算了FNAL E772 800GeV的质子打击不同原子核的Drell-Yan过程截面比,发现考虑能量损失的计算结果与FNAL E772实验数据符合甚好．建议在利用核Drell-Yan过程实验数据抽取束缚核子内部分子分布函数时应该考虑能量损失效应．

The energy loss of the quark in the nuclear matter can be well described by the nuclear dependence in the high energy nuclear Drell-Yan process. In terms of the parametrization of the quark energy loss given in the literature and the nuclear parton distribution extracted from the experimental data of the deep inelastic scattering between lepton and nucleus only, the cross section ratios of lepton pair production in the nuclear Drell-Yan process induced by a proton of 800GeV bombarding on various nuclear targets at E772-FNAL are analyzed. It is shown that our results with the energy loss effect are in good agreement with the E772-FNAL data. Therefore, in order to extract the parton distribution functions in nucleus from the experimental data of the Drell-Yan process reliably, the energy loss effect should be taken into account.