Thursday, February 12, 2009

Spin Crisis

Spin is a fundamental intrinsic property of elementary particles. QCD, Quantum Chromodynamics, should allow us to calculate the spin of a nucleon, a proton or neutron, from its component quarks and gluons. Currently there is no satisfactory explanation of the nucleon spin in terms of QCD. See Spin Structure of the Nucleon - Status and Recent Results.