论文标题
核子核子准-PDF的晶格连续限制研究
Lattice continuum-limit study of nucleon quasi-PDFs
论文作者
论文摘要
准PDF方法提供了使用晶格QCD计算Parton分布函数（PDFS）的途径。这种方法需要在高动量下以核子核子中的幂散发运算符的矩阵元素，并且人们普遍期望离散化效果从晶格间距$ a $ a $ a开始。因此，重要的是要证明可以可靠地采取连续性极限并了解晶格伪影的大小和形状。在这项工作中，我们报告了使用$ n_f = 2+1+1 $ Wilson Twisted Mose Fermions，大约370 MEV和三个不同的晶格间隔的晶格合奏对等异源性和螺旋性PDF的计算。我们的结果表明，对$ a $的依赖有很大的依赖，并且连续外推与现象学产生了更好的一致性。对于小动量分数$ x $的Antiquark分布而言，后者尤其如此，其中推断会改变其标志。
The quasi-PDF approach provides a path to computing parton distribution functions (PDFs) using lattice QCD. This approach requires matrix elements of a power-divergent operator in a nucleon at high momentum and one generically expects discretization effects starting at first order in the lattice spacing $a$. Therefore, it is important to demonstrate that the continuum limit can be reliably taken and to understand the size and shape of lattice artifacts. In this work, we report a calculation of isovector unpolarized and helicity PDFs using lattice ensembles with $N_f=2+1+1$ Wilson twisted mass fermions, a pion mass of approximately 370 MeV, and three different lattice spacings. Our results show a significant dependence on $a$, and the continuum extrapolation produces a better agreement with phenomenology. The latter is particularly true for the antiquark distribution at small momentum fraction $x$, where the extrapolation changes its sign.
