微扰QCD对Drell-Yan过程能量损失效应的修正(英文)

Next-to-Leading Order QCD Corrections to Energy Loss Effect in Drell-Yan Process

利用Glauber模型以及DGLAP方程下的核内核子的部分子分布函数,在次领头阶QCD下计算了Drell- Yan过程中的能量损失效应,计算表明QCD修正并不能改善理论结果与试验结果的符合,尤其是p-W与p-Be以 x1为变量的微分截面比．原因是所用的核内核子部分子的分布函数是以领头阶近似为基础并通过演化方程得到的．于是利用在次领头阶微扰QCD下得到的核遮蔽效应核内核子的部分子分布函数重新计算了次领头阶QCD 修正对Drell-Yan过程能量损失的贡献．计算结果表明康普顿散射过程与湮没过程中应该有更多的能量损失．

In this paper, by means of the nuclear parton distribution obtained from the DGLAP equation,taking into account the energy loss of the beam proton through the nucleus, we analyze the QCD corrections to the measured Drell-Yan production cross sections for an 800GeV proton beam incident on Be, Fe and W nuclear targets in the Glauber model. For the nuclear parton distribution being extracted from the leading order, the results show that the QCD corrections can＇t improve the theoretical results fitting to the experimental data,especially in the cross section ratio of p-W to p-Be verse x1. Then we calculate the Drell-Yan cross sections using the shadowing effect, which is extracted from the next-to-leading order by Frankfurt et al., and find that direct photon production should be sensitive to energy loss in Compton scattering and annihilation process.