Physical Review D
We present the first exploratory lattice quantum chromodynamics (QCD) calculation of the polarized gluon Ioffe-time pseudodistribution in the nucleon. The Ioffe-time pseudodistribution provides a frame-independent and gauge-invariant framework to determine the gluon helicity in the nucleon from first principles. We employ a high-statistics computation using a 323 × 64 lattice ensemble characterized by a 358 MeV pion mass and a 0.094 fm lattice spacing. We establish the pseudodistribution approach as a feasible method to address the proton spin puzzle with successive improvements in statistical and systematic uncertainties anticipated in the future. Within the statistical precision of our data, we find a good comparison between the lattice determined polarized gluon Ioffe-time distribution and the corresponding expectations from the state-of-the-art global analyses. We find a hint for a nonzero gluon spin contribution to the proton spin from the model-independent extraction of the gluon helicity pseudodistribution over a range of Ioffe-time, ν ≲ 9.
Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International (CC BY 4.0) license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI. Funded by SCOAP3.
Original Publication Citation
Egerer, C., Joó, B., Karpie, J., Karthik, N., Khan, T., Monahan, C., Morris, W., Orginos, K., Radyushkin, A., Richards, D., Romero Alcalde, E., Sufian, R., & Zafeiropoulos, S. (2022). Toward the determination of the gluon helicity distribution in the nucleon from lattice quantum chromodynamics. Physical Review D, 106, 1-22, Article 094511. https://doi.org/10.1103/PhysRevD.106.094511
Egerer, Colin; Joó, Bálint; Karpie, Joseph; Karthik, Nikhil; Khan, Tanjib; Monahan, Christopher J.; Morris, Wayne; Orginos, Kostas; Radyushkin, Anatoly; Richards, David G.; Romero, Eloy; Sabbir Sufian, Raza; and Zafeiropoulos, Savvas, "Toward the Determination of the Gluon Helicity Distribution in the Nucleon from Lattice Quantum Chromodynamics" (2022). Physics Faculty Publications. 708.