Explore the intricate details of angular momentum distributions within the proton in this 34-minute lecture by Yoshitaka Hatta from the International Centre for Theoretical Sciences. Delve into advanced concepts related to hadron structure and the upcoming Electron-Ion Collider (EIC) experiments. Gain insights into how quarks and gluons contribute to the proton's spin and orbital angular momentum, a key question the EIC aims to investigate. Learn about cutting-edge research in particle physics, quantum chromodynamics (QCD), and nuclear physics as part of the International School and Workshop on Probing Hadron Structure at the Electron-Ion Collider program.