Highlights of Spin Study at JLab Hall A: Longitudinal and Transverse

摘要

Spin‐dependent observables have been a powerful tool to probe the internal structure of the nucleon and to understand the dynamics of the strong interaction. Experiments involving spin degrees of freedom have lead to numerous surprises, puzzles and discoveries. The so called "spin crisis" in the 1980s revealed the limitation of naive quark‐parton models and led to intensive worldwide efforts, both experimental and theoretical, to understand the nucleon spin structure. The nucleon spin structrue study has grown from mainly on the longitudinal spin in the last thirty years to recently rapidly increasing interests on the transverse spin. With high intensity and high polarization of both the electron beam and targets, JLab has the world's highest polarized luminosity and the best figure‐of‐merit for precision spin structure measurements. It has made a strong impact in this subfield of research. This proceeding will highlight JLab Hall A's study in the measurements of the moments of spin structure functions at low‐to‐intermediate Q~2 and in the transverse spin structure.