String-based axial and helicity-flip GPDs: A comparison to lattice QCD

Journal Article · Thu Oct 16 00:00:00 EDT 2025 · Physical Review. D.

DOI:https://doi.org/10.1103/7lxw-g6tq· OSTI ID:3021120

Hechenberger, Florian ^[1]; Mamo, Kiminad A. ^[2]; Zahed, Ismail ^[1]

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1. Stony Brook University, NY (United States)
2. College of William and Mary, Williamsburg, VA (United States)

We construct an analytic, string-based representation of the nucleon’s axial and helicity-flip conformal moments of generalized parton distributions (GPDs) that holds for skewness and for both the quark and gluon channels. The starting point is the Mellin-Barnes resummation of the conformal partial-wave expansion, where the moments are parametrized by open- (Reggeon) and closed-string (Pomeron) trajectories with slopes determined by experimental form factors and meson/glueball spectroscopy. The forward limits are fixed by the empirical unpolarized and polarized parton distributions. Polynomiality, crossing symmetry, and support are satisfied by construction. After next-to-leading order Dokshitzer-Gribov-Lipatov-Altarelli-Parisi/Efremov-Radyushkin-Brodsky-Lepage evolution to μ = 2 GeV our analytic framework (i) reproduces some of the currently available lattice moments of E and H˜ in the nonsinglet sector, (ii) predicts sea-quark and gluon polarized moments that will be testable by forthcoming simulations and experiments at Jefferson Lab and the future Electron-Ion Collider, and (iii) yields axial and helicity-flip GPDs in x-space in reasonable agreement with lattice QCD.

• Research Organization: Stony Brook University, NY (United States)
• Sponsoring Organization: USDOE
• Grant/Contract Number: AC05-06OR23177; FG02-04ER41302; FG02-88ER40388; SC0023646
• Other Award/Contract Number: FG-88ER40388
• OSTI ID: 3021120
• Journal Information: Physical Review. D., Journal Name: Physical Review. D. Journal Issue: 7 Vol. 112; ISSN 2470-0010; ISSN 2470-0029
• Publisher: American Physical Society (APS)
• Country of Publication: United States
• Language: English

Related Subjects

Gauge-gravity dualities
Generalized parton distributions
Nucleon spin structure