Numerical Study of Single-Inclusive Longitudinal-Transverse Double-Spin Asymmetries in Electron-Proton and Proton-Proton Collisions

High-energy collisions allow us to probe the interaction of quarks and gluons, which make up the internal structure of hadrons. In the aftermath of these collisions, other particles are formed, such as pions. These pions are produced in different quantities and directions depending on the type of collision and the orientation of the spins of the initial-state particles involved. These asymmetries can be measured in experiments. Our research focuses on the asymmetry A_LT involving a longitudinally polarized electron or proton colliding with a transversely polarized proton, with a single pion detected in the final state. We have provided updated, more rigorous numerical predictions using new information on the functional form of parton distribution functions (PDFs) and fragmentation functions (FFs) involved in calculating A_LT. Predictions have been made for Jefferson Lab, COMPASS, RHIC, and the future Electron-Ion Collider. By generating these predictions, we hope to gain more insight into the quark-gluon-quark interactions that occur inside of hadrons.

This work is supported by the National Science Foundation under Grant No. PHY-2011763.