Transverse Single-Spin Asymmetries in Inclusive DIS and SIDIS Production of Photons: Numerical Predictions using Models for Multi-Parton Correlators*

High-energy collisions between unpolarized electrons and nucleons allow for the probing of the internal structure of nucleons (protons and neutrons). This can be accomplished through the use of inclusive deep inelastic scattering (DIS), where only the scattered electron is detected, or semi-inclusive deep inelastic scattering (SIDIS), where also another final-state particle is detected. If the nucleon is transversely polarized, a spin asymmetry A_UT can be computed that is sensitive to quark-gluon-quark (qgq) correlators in the nucleon.  These functions are not well known, especially in the region where the two quarks carry different momentum fractions.  In this vein, we present here rigorously conducted numerical analyses of A_UT for inclusive DIS as well as SIDIS with a final-state photon in order to test models for qgq functions and motivate future experiments. We compute A_UT for both proton and neutron targets and compare to relevant DIS experimental data from the Jefferson Lab and HERMES as well as make predictions for DIS and “gamma-SIDIS” at the Electron-Ion Collider. In the latter case we thoroughly explore the phase space in order to identify the kinematics where the asymmetry could be measurable. This quantitative analysis of these models hopes to advance our understanding of quark-gluon-quark correlators, especially in anticipation of the EIC.