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arXiv 1702.05077hep-ph
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最近的RHIC数据对螺旋度相关的部分子分布函数的影响

Impact of Recent RHIC Data on Helicity-Dependent Parton Distribution Functions

Emanuele R. Nocera

摘要:

我研究最近的测量在相对论重离子对撞机上进行的螺旋度依赖的部分子分布函数的质子的测定的影响。具体而言,我认为:2013年运行期间STAR实验在质量中心能量$\sqrt{s}=510$ GeV下记录的$W$ -玻色子产生的纵向单自旋不对称性的初步数据; 2009年运行期间STAR实验在$\sqrt{s}=200$ GeV下记录的双喷流产生的纵向双自旋不对称性的数据;数据显示,双... 2006年至2013年期间,在$\sqrt{s}=200$ GeV和$\sqrt{s}=510$上进行的一系列运行期间,PHENIX实验记录了中性π介子产生的自旋不对称性GeV。新数据的影响进行了研究,通过应用贝叶斯重新加权NNPDFpol1.1,最近的全球分析螺旋度相关的部分子分布函数的基础上的NNDPF方法。与NNDPFpol1.1相比,NNDPFpol1.1的极化胶子概率密度函数具有更大的正极性,扩展到更小的动量分数值,不确定度更小,极化上下海夸克之间的不对称性也更显著和精确.

英文摘要:

I study the impact of recent measurements performed at the Relativistic Heavy Ion Collider on the determination of helicity-dependent parton distribution functions of the proton. Specifically, I consider: preliminary data on longitudinally single-spin asymmetries for $W$-boson production recorded by the STAR experiment during the 2013 run at a center-of-mass energy $\sqrt{s}=510$ GeV; data on longitudinally double-spin asymmetries for di-jet production recorded by the STAR experiment during the 2009 run at $\sqrt{s}=200$ GeV; and data on longitudinally double-spin asymmetries for neutral pion production recorded by the PHENIX experiment during a series of runs between 2006 and 2013 at $\sqrt{s}=200$ GeV and $\sqrt{s}=510$ GeV. The impact of the new data is studied by applying Bayesian reweighting to NNPDFpol1.1, the most recent global analysis of helicity-dependent parton distribution functions based on the NNDPF methodology. In comparsion to NNDPFpol1.1, a slightly more positive polarized gluon PDF, extended to somewhat smaller values of momentum fractions with narrower uncertainties, as well as a slightly more marked and more precise asymmetry between polarized up and down sea quarks are found in this study.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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