Constraining the Polarized Gluon Distribution of the Nucleon with Experimental and Lattice Data

Quantifying the partonic contributions to the spin of the proton has been a long-standing challenge for quantum chromodynamics (QCD), the theory of the strong nuclear force. The contribution from gluons, in particular, is still largely unknown, in part because the polarized gluon parton distribution function (PDF) is poorly constrained by current experimental data. We study the polarized gluon PDF of the nucleon through a Monte Carlo global QCD analysis of experimental data and pseudo-distributions determined from lattice QCD. We show that the inclusion of lattice QCD data helps constrain the behavior of the polarized gluon PDF at moderate values of Ioffe-time, demonstrating the importance of lattice QCD as a tool for understanding hadron structure, particularly for quantities that are poorly constrained by experimental data alone.