Moments of Nucleon Unpolarized, Polarized, and Transversity Parton Distribution Functions from Lattice QCD at the Physical Point

Abstract

The second Mellin moments $⟨x⟩$ of the nucleon's unpolarized, polarized, and transversity parton distribution functions (PDFs) are computed. Two lattice QCD ensembles at the physical pion mass are used: these were generated using a tree-level Symanzik-improved gauge action and 2+1 flavour tree-level improved Wilson Clover fermions coupling via 2-level HEX-smearing. The moments are extracted from forward matrix elements of local leading twist operators. We determine renomalization factors in RI-(S)MOM and match to $\overline{\mathrm{MS}}$ at scale $2\mathrm{GeV}$. Our findings show that operators that exhibit vanishing kinematics at zero momentum can have significantly reduced excited-state contamination. The resulting polarized moment is used to quantify the longitudinal contribution to the quark spin-orbit correlation. All our results agree within two sigma with previous lattice results.

References in corpus (11)

• New parton distributions for collider physics
• Generalized parton correlation functions for a spin-1/2 hadron
• Quark Wigner Distributions and Orbital Angular Momentum
• Adaptive multigrid algorithm for the lattice Wilson-Dirac operator
• QCD Analysis of the Polarized World Data
• Lattice QCD at the physical point: light quark masses
• The x-dependence of hadronic parton distributions: A review on the progress of lattice QCD
• Nucleon axial, scalar, and tensor charges using lattice QCD at the physical pion mass
• Toward $N$ to $N\pi$ matrix elements from lattice QCD
• Two loop renormalization of the n = 2 Wilson operator in the RI'/SMOM scheme
• Moments $n=2$ and $n=3$ of the Wilson twist-two operators at three loops in the RI${}^{\prime }$/SMOM scheme

Cited by in corpus (2)

• FLAG Review 2024
• Moments of Axial-Vector GPD from Lattice QCD: Quark Helicity, Orbital Angular Momentum, and Spin-Orbit Correlation