Lattice QCD Calculation of Gluon Contribution to Proton Spin

Published:Dec 30, 2025 16:10
1 min read
ArXiv

Analysis

This paper presents a cutting-edge lattice QCD calculation of the gluon helicity contribution to the proton spin, a fundamental quantity in understanding the internal structure of protons. The study employs advanced techniques like distillation, momentum smearing, and non-perturbative renormalization to achieve high precision. The result provides valuable insights into the spin structure of the proton and contributes to our understanding of how the proton's spin is composed of the spins of its constituent quarks and gluons.

Reference

The study finds that the gluon helicity contribution to proton spin is $ΔG = 0.231(17)^{\mathrm{sta.}}(33)^{\mathrm{sym.}}$ at the $\overline{\mathrm{MS}}$ scale $μ^2=10\ \mathrm{GeV}^2$, which constitutes approximately $46(7)\%$ of the proton spin.