Impacts of B-factory measurements on determination of fragmentation functions from electron-positron annihilation data
Impacts of B-factory measurements on determination of fragmentation functions from electron-positron annihilation data
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DOI：
10.1093/ptep/ptw154
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发表时间：
2016-08
期刊：
影响因子：
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通讯作者：
M. Hirai;M. Hirai;H. Kawamura;H. Kawamura;S. Kumano;K. Saito
中科院分区：
文献类型：
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作者：
M. Hirai;M. Hirai;H. Kawamura;H. Kawamura;S. Kumano;K. Saito
通过对正负电子湮灭中带电强子产生数据的全局分析，确定了π介子和K介子的碎裂函数。贝儿和巴巴尔合作组分别在KEK和SLAC B工厂报道了在10.52 GeV和10.54 GeV质心能量下的碎裂函数的精确测量结果，而其他可用的e^+e^-测量大多是在更高的能量下进行的，主要是在91.2 GeV的Z$质量下。有一种可能性，胶子碎裂函数，以及夸克碎裂函数，准确地确定标度破坏。我们报告我们的全球分析的碎片功能，特别是显示的B-工厂测量的碎片功能的确定的影响。我们的研究结果表明，破碎功能更准确地确定不仅由标度破坏，但也由高统计性质的贝儿和BaBar数据。然而，与以前的测量相比，贝儿和巴巴尔的数据之间存在一些紧张关系。我们还解释了如何通过使用不同的Q^2 $值的测量来分离夸克碎裂函数和胶子函数的味依赖性。特别是，电和弱的变化是不同的夸克类型，使轻夸克的味道分离也成为可能的原则，由于在$\sqrt{s}\simeq 10.5$ GeV和91.2 GeV的精确数据。
Fragmentation functions are determined for the pion and kaon by global analyses of charged-hadron production data in electron-positron annihilation. Accurate measurements were reported by the Belle and BaBar collaborations for the fragmentation functions at the center-of-mass energies of 10.52 GeV and 10.54 GeV, respectively, at the KEK and SLAC B factories, whereas other available $e^+e^-$ measurements were mostly done at higher energies, mainly at the $Z$ mass of 91.2 GeV. There is a possibility that gluon fragmentation functions, as well as quark fragmentation functions, are accurately determined by scaling violation. We report our global analysis of the fragmentation functions especially to show impacts of the B-factory measurements on the fragmentation function determination. Our results indicate that the fragmentation functions are determined more accurately not only by the scaling violation but also by high-statistical nature of the Belle and BaBar data. However, there are some tensions between the Belle and BaBar data in comparison with previous measurements. We also explain how the flavor dependence of quark fragmentation functions and the gluon function are separated by using measurements at different $Q^2$ values. In particular, the electric and weak changes are different depending on the quark type, so that a light-quark flavor separation also became possible in principle due to the precise data at both $\sqrt{s}\simeq 10.5$ GeV and 91.2 GeV.