Speaker
Description
The large-momentum effective theory (LaMET) is a systematic approach to calculate parton physics from Euclidean approaches such as lattice QCD. With major improvements in the non-perturbative renormalization and perturbative matching, the lattice calculation of PDFs with LaMET is now entering the stage of precision control. In this talk, I will present a state-of-the-art lattice QCD calculation of pion valence quark distribution with the hybrid scheme and the first-time implementation of next-to-next-to-leading order matching correction, which is done using two fine lattices with spacings a=0.04 fm and 0.06 fm and valence pion mass 300 MeV at boost momentum as large as 2.42 GeV. I will demonstrate that the renormalization and the perturbative matching in Bjorken-$x$ space yields a reliable determination of the valence quark distribution for moderate x with controlled systematic uncertainties, which is in nice agreement with the most recent global analyses.
