标题： 具有扭曲质量费米子的部分子分布函数 显示英文标题

标题： Parton Distribution Functions with Twisted Mass Fermions

摘要： 我们展示了首个关于味扭失真质量费米子在π介子态之间扭曲-2算符矩阵元的计算，该算符与π介子中价夸克部分子分布函数的最低矩<x>有关。 使用味扭失真质量费米子的淬火近似，我们证明<x>可以在较小的赝标介子质量下计算，低至约250 MeV。 通过应用两种临界质量定义，我们研究了这一物理上重要的量的尺度行为，观察到在两种情况下均与预期的O(a^2)行为一致。 一个联合的连续外推允许在非常小的赝标介子质量下获得可靠的结果<x>，这在以前的格点QCD模拟中无法探索。 显示英文摘要

摘要： We present a first Wilson twisted mass fermion calculation of the matrix element between pion states of the twist-2 operator, which is related to the the lowest moment < x > of the valence quark parton distribution function in a pion. Using Wilson twisted mass fermions in the quenched approximation we demonstrate that < x > can be computed at small pseudoscalar meson masses down to values of order 250 MeV. We investigate the scaling behaviour of this physically important quantity by applying two definitions of the critical mass and observe a scaling compatible with the expected O(a^2) behaviour in both cases. A combined continuum extrapolation allows to obtain reliable results for < x > at very small pseudoscalar meson masses, which previously could not be explored by lattice QCD simulations.