Quark spin in the proton
arXiv:1004.4977 · doi:10.1142/9789814335614_0049
Abstract
The proton spin puzzle has challenged our understanding of QCD for the last 20 years. We survey new developments in theory and experiment. The proton spin puzzle seems to be telling us about the interplay of valence quarks with chiral dynamics and the complex vacuum structure of QCD.
8 pages, presented at the Conference in Honour of Murray Gell-Mann's 80th Birthday: Quantum Mechanics, Elementary Particles, Quantum Cosmology and Complexity, NTU, Singapore, 24th-26th February 2010