[RBRC Seminar] Probing the Nucleon's Spin Structure: A String-Based Approach to Generalized Parton Distributions

by Florian Hechenberger (Stony brook)

Thursday 5 Jun 2025, 12:30 → 14:30 US/Eastern

2-160 (https://bnl.zoomgov.com/j/1600983728?pwd=RAD7OLcqre7Ycsp6JfFp6HAnpyLxex.1)

I discuss an extension of the formalism developed in Phys.Rev.Lett. 133 (2024) 24, 241901 to helicity generalized parton distributions (GPDs) with the skewness dependence modeled by t-channel exchanges of spin-j operators in AdS space. Based on the conformal moment expansion, the GPDs are obtained through Mellin-Barnes integrals which bypass the deconvolution problem and are valid for all values of the skewness parameter. With a minimal set of free parameters and the helicity parton distribution functions (PDFs) from the Asymmetry Analysis Collaboration (AAC) as an input, we predict the functional dependence of the conformal moments which enables us to construct the isoscalar, isovector, flavor separated and singlet quark and gluon helicity GPDs. Additionally, we compute the impact parameter representation of the associated helicity, angular momentum and spin-orbit contributions of the valence and sea constituents, enabling a full tomographic analysis of the proton spin decomposition.