论文标题
晶格QCD的核子中魅力不对称性的限制
Constraints on charm-anticharm asymmetry in the nucleon from lattice QCD
论文作者
论文摘要
我们介绍了对核子电磁形式贡献的第一个晶格QCD计算$ g^c_ {e，m}（q^2）$在动量转移范围内$ 0 \ leq q^2 \ leq 1.4 $ $ $ $ \ rm gev^2 $。夸克质量依赖性，有限的晶格间距和体积校正是根据对三个量规合奏的计算，包括物理脉冲质量的三个量规合奏的计算。魅力磁矩的非零值$μ^c_m = -0.00127（38）_ {\ rm stat}（5）_ {\ rm sys} $以及Pauli form recors，反映了Charm Sea在核子自旋结构中的非谋生作用。非零$ g^c_ {e}（q^2）$表示存在非对称的不对称魅力 - 安提克在核中存在。我们基于全息QCD和广义的委内撒模型进行非扰动分析，我们研究了此处介绍的lattice QCD结果的$ [C（x） - \ bar {c}（x）] $分布的约束。我们的结果为对内在魅力敏感的物理可观察物以及对Parton分布（包括不对称魅力 - 安提卡姆分布）的全球分析提供了更详细的研究提供了互补的信息和动力。
We present the first lattice QCD calculation of the charm quark contribution to the nucleon electromagnetic form factors $G^c_{E,M}(Q^2)$ in the momentum transfer range $0\leq Q^2 \leq 1.4$ $\rm GeV^2$. The quark mass dependence, finite lattice spacing and volume corrections are taken into account simultaneously based on the calculation on three gauge ensembles including one at the physical pion mass. The nonzero value of the charm magnetic moment $μ^c_M=-0.00127(38)_{\rm stat}(5)_{\rm sys}$, as well as the Pauli form factor, reflects a nontrivial role of the charm sea in the nucleon spin structure. The nonzero $G^c_{E}(Q^2)$ indicates the existence of a nonvanishing asymmetric charm-anticharm sea in the nucleon. Performing a nonperturbative analysis based on holographic QCD and the generalized Veneziano model, we study the constraints on the $[c(x)-\bar{c}(x)]$ distribution from the lattice QCD results presented here. Our results provide complementary information and motivation for more detailed studies of physical observables that are sensitive to intrinsic charm and for future global analyses of parton distributions including asymmetric charm-anticharm distribution.
