Abstract We investigate the nucleon and pion gluon distribution functions in the framework of holographic QCD, focusing on the small Bjorken x region. Based on an approximate relation, the gluon distributions are extracted from structure functions of the unpolarized deep inelastic scattering which can be calculated with a holographic QCD model, assuming the Pomeron exchange. All the adjustable parameters of the model are determined with the HERA data of the proton structure functions. We explicitly show that the extracted proton gluon distribution is consistent with results of the recent global QCD analysis. The structure functions of the pion can be computed without any additional parameter, which enables us to predict its gluon distribution also. We find that the resulting pion gluon density is smaller than the proton's, and agrees with the recent global QCD analysis result within the uncertainties.

中文翻译：

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从全息 QCD 中小 x 处的结构函数中提取胶子分布

摘要 我们研究了全息 QCD 框架中的核子和 pion 胶子分布函数，重点是小 Bjorken x 区域。基于近似关系，胶子分布是从非极化深非弹性散射的结构函数中提取的，假设 Pomeron 交换，可以使用全息 QCD 模型计算该结构函数。模型的所有可调参数均由质子结构函数的HERA数据确定。我们明确表明提取的质子胶子分布与最近的全球 QCD 分析结果一致。可以在没有任何附加参数的情况下计算 pion 的结构函数，这也使我们能够预测它的胶子分布。我们发现由此产生的π介子胶子密度小于质子，