标题： 物理连续极限下的格点核子同位旋非极化部分子分布函数 显示英文标题

标题： Lattice Nucleon Isovector Unpolarized Parton Distribution in the Physical-Continuum Limit

摘要： 我们首次利用大动量有效理论（LaMET）在物理连续极限下进行了核子同位旋矢量非极化部分子分布函数（PDFs）的格点QCD计算。 格点结果使用了多重海π介子质量的组合进行计算，其中最轻的约为135 MeV，三种晶格间距分别为$a\in[0.06,0.12]$fm，以及多个体积，其中$M_\pi L$范围从3.3到5.5。 我们在物理π介子质量下的连续极限中，同时进行手征-连续性外推，以获得RI/MOM归一化的核子矩阵元，这些矩阵元具有不同的Wilson链位移。 然后，我们应用一阶微扰论匹配来得到光锥PDFs。 我们发现对于这些LaMET矩阵元，晶格间距依赖性远大于π介子质量和晶格体积的依赖性。 我们发现物理连续极限下的非极化同位旋矢量核子PDFs与全球PDF结果一致。 显示英文摘要

摘要： We present the first lattice-QCD calculation of the nucleon isovector unpolarized parton distribution functions (PDFs) at the physical-continuum limit using Large-Momentum Effective Theory (LaMET). The lattice results are calculated using ensembles with multiple sea pion masses with the lightest one around 135~MeV, 3 lattice spacings $a\in[0.06,0.12]$~fm, and multiple volumes with $M_\pi L$ ranging 3.3 to 5.5. We perform a simultaneous chiral-continuum extrapolation to obtain RI/MOM renormalized nucleon matrix elements with various Wilson-link displacements in the continuum limit at physical pion mass. Then, we apply one-loop perturbative matching to the quasi-PDFs to obtain the lightcone PDFs. We find the lattice-spacing dependence to be much larger than the dependence on pion mass and lattice volume for these LaMET matrix elements. Our physical-continuum limit unpolarized isovector nucleon PDFs are found to be consistent with global-PDF results.