LHCb√s=8 TeV的Drell-Yan-Z→e^+e^-数据对部分子分布函数的影响

Impacts of Drell-Yan-Z Data in L HCb√s=8TeV on the Parton Distribution Functions

大型强子对撞机(LHC)上的LHCb探测器利用质心能量为8 TeV的质子-质子(p-p)对撞实验测量了过程pp→Z^*+X→e^++e^-+X的总散射截面及微分散射截面.该实验数据在确定奇异夸克部分子分布函数(PDF)的精确度方面非常重要.文章利用ResBos和CT14NNLO部分子分布函数计算出此过程的总散射截面和微分散射截面,并与LHCb实验结果进行比较.进一步,用ePump更新CT14NNLO部分子分布函数.结果显示,新的奇异夸克PDF在Q=1.3 GeV,10^-6<x<0.2的范围内误差有明显缩小.实验数据对于能量尺度为Q=100GeV的奇异夸克PDF没有明显的影响.

The total and differential scattering cross sections of the process pp→Z^*+X→e^++e^-+X are measured in p-p collision at a center-mass energy of 8 TeV with the LHCb detector at the LHC,which are important for determining the accuracy of strange quark parton distribution functions.In this paper,the total and the differential scattering cross sections of the process are calculated by ResBos and CT14 NNLO PDFs,which are compared with the LHCb experiment data,then the CT14 NNLO PDF is updated with ePump.The results show that the error of new strange quark parton distribution function with the energy scale of Q=1.3 GeV significantly reduces in the range of 10^-6<x<0.2,while the experimental data has no obvious effect on the strange quark PDF with the energy scale of Q=100.0 GeV.