Confinement through mirroring is possible because this quantity is an (*) adiabatic invariant.
Form factor F2 of the vertex function equals a contributor to this quantity. The E821 experiment attempted to measure a value of this type which deviates from Standard Model predictions by 3.4 standard deviations. The fact that deuterons have a smaller value for this quantity than protons reveals that it is negative for a neutron. Confinement through mirroring is possible because this quantity is an (*) adiabatic invariant. In g−2 [g minus 2] experiments, the "anomalous" portion of this quantity is measured, whose one-loop correction is  equal to the fine structure constant over 2 pi. The ratio of this quantity to a particle's angular momentum is the gyromagnetic ratio. A constant defined as fundamental charge times h-bar over 2 times the electron mass is used as the unit for this property for an electron, and is named for Bohr. For 10 points, name this quantity equal to the current of a loop times its area, which indicates how much torque an object will experience in a magnetic field.
Form factor F2 of the vertex function equals a contributor to this quantity.
magnetic moment [or magnetic dipole moment; accept anomalous magnetic dipole moment] 