2026-06-11 アルゴンヌ国立研究所（ANL）
Graphic showing the transverse motion of a quark (green sphere) inside a proton whose spin is aligned to its direction of motion (large yellow arrow). (Image by Valerie Lentz/Brookhaven National Laboratory.)
＜関連情報＞
- https://www.anl.gov/article/researchers-use-argonne-supercomputer-to-illuminate-the-subatomic-particle-that-helps-hold-matter
- https://link.springer.com/article/10.1007/JHEP02(2025)056
格子QCDを用いたパイオンの三次元イメージング：一般化されたパートン分布 Three-dimensional imaging of pion using lattice QCD: generalized parton distributions
Heng-Tong Ding,Xiang Gao,Swagato Mukherjee,Peter Petreczky,Qi Shi,Sergey Syritsyn & Yong Zhao
Journal of High Energy Physics Published:11 February 2025
DOI:https://doi.org/10.1007/JHEP02(2025)056 preprint version
Abstract
In this work, we report a lattice calculation of x-dependent valence pion generalized parton distributions (GPDs) at zero skewness with multiple values of the momentum transfer −t. The calculations are based on an Nf = 2 + 1 gauge ensemble of highly improved staggered quarks with Wilson-Clover valence fermion. The lattice spacing is 0.04 fm, and the pion valence mass is tuned to be 300 MeV. We determine the Lorentz-invariant amplitudes of the quasi-GPD matrix elements for both symmetric and asymmetric momenta transfers with similar values and show the equivalence of both frames. Then, focusing on the asymmetric frame, we utilize a hybrid scheme to renormalize the quasi-GPD matrix elements obtained from the lattice calculations. After the Fourier transforms, the quasi-GPDs are then matched to the light-cone GPDs within the framework of large momentum effective theory with improved matching, including the next-to-next-to-leading order perturbative corrections, and leading renormalon and renormalization group resummations. We also present the 3-dimensional image of the pion in impact-parameter space through the Fourier transform of the momentum transfer −t.
