Unpolarized isovector quark distribution function from lattice QCD: a systematic analysis of renormalization and matching

Abstract

Lattice Parton Collaboration (Liu, Yu-Sheng, et al.), "Unpolarized isovector quark distribution function from lattice QCD: a systematic analysis of renormalization and matching." Physical Review D 101 (Feb. 2020): no. 034020 doi 10.1103/PhysRevD.101.034020 ©2020 Author(s)We present a detailed lattice QCD study of the unpolarized isovector quark parton distribution function (PDF) using a large-momentum effective theory framework. We choose a quasi-PDF defined by a spatial correlator which is free from mixing with other operators of the same dimension. In the lattice simulation, we use a Gaussian-momentum-smeared source at M[subscript p]=356  MeV and P[subscript z]∈{1.8,2.3}  GeV. To control the systematics associated with the excited states, we explore five different source-sink separations. The nonperturbative renormalization is conducted in a regularization-independent momentum subtraction scheme, and the matching between the renormalized quasi-PDF and [line over MS] PDF is calculated based on perturbative QCD up to one-loop order. Systematic errors due to renormalization and perturbative matching are also analyzed in detail. Our results for light-cone PDF are in reasonable agreement with the latest phenomenological analysis. ©202