Parton distributions with LHC data
Parton distributions with LHC data
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DOI：
10.1016/j.nuclphysb.2012.10.003
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发表时间：
2013-02-11
影响因子：
2.8
通讯作者：
Ubiali, Maria
中科院分区：
文献类型：
--
作者：
Ball, Richard D.;Bertone, Valerio;Ubiali, Maria
我们提出了第一次确定的部分子分布的核子在NLO和NNLO的基础上的全球数据集，其中包括LHC数据：NNPDF2.3。我们的数据集包括，除了深度非弹性，Drell-Yan，规范玻色子生产和喷流数据已经在以前的全球PDF测定中使用，所有相关的LHC数据，实验系统的不确定性是目前可用的：2010年运行的ATLAS和LHCb W和Z快度分布，2011年运行的CMS W电子不对称数据，以及2010年运行的ATLAS包含射流横截面。我们介绍了一种改进的实现的FastKernel方法，使我们能够适应这个扩展的数据集，并采取更有效的最小化方法。我们提出了NNPDF2.3 PDF集，并将其与NNPDF2.1集进行比较，以评估LHC数据的影响。我们发现，所有的大型强子对撞机的数据是广泛一致的，彼此和所有旧的数据集包括在拟合。我们提出了各种标准蜡烛截面的预测。并将其与之前使用NNPDF2.1获得的结果进行比较。并具体讨论了ATLAS电弱数据对质子奇异分数测定的影响。我们还提出了碰撞PDF集，只使用HERA的数据构建。Tevatron和LHC但是发现该数据集对于竞争性PDF确定来说既不精确也不完整。(C)2012爱思唯尔有限公司版权所有。
We present the first determination of parton distributions of the nucleon at NLO and NNLO based on a global data set which includes LHC data: NNPDF2.3. Our data set includes, besides the deep inelastic, Drell-Yan, gauge boson production and jet data already used in previous global PDF determinations, all the relevant LHC data for which experimental systematic uncertainties are currently available: ATLAS and LHCb W and Z rapidity distributions from the 2010 run, CMS W electron asymmetry data from the 2011 run, and ATLAS inclusive jet cross-sections from the 2010 run. We introduce an improved implementation of the FastKernel method which allows us to fit to this extended data set, and also to adopt a more effective minimization methodology. We present the NNPDF2.3 PDF sets, and compare them to the NNPDF2.1 sets to assess the impact of the LHC data. We find that all the LHC data are broadly consistent with each other and with all the older data sets included in the fit. We present predictions for various standard candle cross-sections. and compare them to those obtained previously using NNPDF2.1. and specifically discuss the impact of ATLAS electroweak data on the determination of the strangeness fraction of the proton. We also present collider PDF sets, constructed using only data from HERA. the Tevatron and the LHC. but find that this data set is neither precise nor complete enough for a competitive PDF determination. (C) 2012 Elsevier B.V. All rights reserved.