Theoretical issues in PDF determination and associated uncertainties NNPDF Collaboration
Theoretical issues in PDF determination and associated uncertainties NNPDF Collaboration
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DOI：
10.1016/j.physletb.2013.05.019
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发表时间：
2013-06-25
影响因子：
4.4
通讯作者：
Ubiali, Maria
中科院分区：
文献类型：
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作者：
Ball, Richard D.;Bertone, Valerio;Ubiali, Maria
我们研究了在确定部分子分布(PDF)时可能影响当前用于大型强子对撞机精密物理的PDF集的几个理论不确定性来源，并解释了它们之间的差异。我们特别考虑了固定味道与可变味道数重整化方案、更高的扭曲修正和核修正的使用。我们在NNPDF2.3全球PDF确定的框架下进行研究，在每种情况下量化不同理论假设对输出PDF的影响。我们还研究了每一种情况对大型强子对撞机基准截面的影响。我们发现，固定味道数方案在全球拟合中的影响是相当大的，更高的扭曲的影响可以忽略不计，而核修正的影响是适度的和有限的。(C)2013爱思唯尔B.V.保留所有权利。
We study several sources of theoretical uncertainty in the determination of parton distributions (PDFs) which may affect current PDF sets used for precision physics at the Large Hadron Collider, and explain discrepancies between them. We consider in particular the use of fixed-flavor versus variable-flavor number renormalization schemes, higher twist corrections, and nuclear corrections. We perform our study in the framework of the NNPDF2.3 global PDF determination, by quantifying in each case the impact of different theoretical assumptions on the output PDFs. We also study in each case the implications for benchmark cross sections at the LHC. We find that the impact in a global fit of a fixed-flavor number scheme is substantial, the impact of higher twists is negligible, and the impact of nuclear corrections is moderate and circumscribed. (C) 2013 Elsevier B.V. All rights reserved.