Work

Transverse single-spin asymmetries in γSIDIS as a direct probe of quark-gluon-quark longitudinal momentum structure

Year: 2025

Type: article

Abstract: Transverse single-spin asymmetries in the semi-inclusive deep-inelastic production of isolated photons ( γ SIDIS), A U T γ S I D I S , provide an unprecedented opportunity to extract the quark-gluon-quark correlators F F T ( x , x ′ ) and G F T ( x , x ′ ) point-by-point in their full support x , x ′ . We utilize realistic models for these functions, based on input from the Sivers transverse momentum dependent parton distribution function and imposing constraints from the d 2 matrix element calculated in lattice QCD, in order to provide numerical estimates for A U T γ S I D I S at the Electron-Ion Collider (EIC). We thoroughly explore the EIC phase space in order to isolate in which regions the asymmetry can be sizable, finding it can be as much as 10 % or larger for certain kinematics. Given that F F T ( x , x ′ ) and G F T ( x , x ′ ) are basically unknown, A U T γ S I D I S will be an important future measurement to learn about multi-parton correlations in the nucleon.

Source: Physics Letters B

DOI: 10.1016/j.physletb.2025.139793