Lin Huey-Wen
Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA.
Department of Computational Mathematics, Science and Engineering, Michigan State University, East Lansing, Michigan 48824, USA.
Phys Rev Lett. 2021 Oct 29;127(18):182001. doi: 10.1103/PhysRevLett.127.182001.
We present the first lattice calculation of the nucleon isovector unpolarized generalized parton distribution at the physical pion mass using a lattice ensemble with 2+1+1 flavors of highly improved staggered quarks generated by the MILC Collaboration, with lattice spacing a≈0.09 fm and volume 64^{3}×96. We use momentum-smeared sources to improve the signal at nucleon boost momentum P_{z}≈2.2 GeV and report results at nonzero momentum transfers in [0.2,1.0] GeV^{2}. Nonperturbative renormalization in a regularization-independent momentum-subtraction scheme is used to obtain the quasidistribution before matching to the light-cone generalized parton distributions. The three-dimensional distributions H(x,Q^{2}) and E(x,Q^{2}) at ξ=0 are presented, along with the three-dimensional nucleon tomography and impact parameter-dependent distribution for selected Bjorken x at μ=3 GeV in a modified minimal subtraction scheme.
我们展示了在物理π介子质量下，使用由MILC合作组生成的具有2 + 1 + 1味高度改进交错夸克的格点系综，对核子同位旋矢量非极化广义部分子分布进行的首次格点计算，格点间距(a≈0.09)飞米，体积为(64^{3}×96)。我们使用动量涂抹源来改善在核子推进动量(P_{z}≈2.2)吉电子伏时的信号，并报告在([0.2,1.0])吉电子伏²的非零动量转移下的结果。在正则化无关的动量减法方案中的非微扰重整化用于在与光锥广义部分子分布匹配之前获得准分布。给出了在(\xi = 0)时的三维分布(H(x,Q^{2}))和(E(x,Q^{2}))，以及在修正的最小减法方案中，在(\mu = 3)吉电子伏时，针对选定的比约肯(x)的三维核子断层扫描和与碰撞参数相关的分布。
