On the axial charge g_{A} and the quark confinement in nucleons
Abstract
Calculations are presented of the axial charge g_{A} in models where relativistic quarks are confined by arbitrary vector potentials, scalar potentials ~ r^{n} and scalarvector potentials ~ 1/2(1+γ_{0})r^{n} for arbitrary n >= 0. It is shown that g_{A} vanishes for all vector potentials and is a monotonically decreasing function of the exponent n for scalar and scalarvector potentials. The nonrelativistic value 5/3 is reproduced (for n = 0) as well as the MIT bag model value 1.09 (for n > ∞) they are upper and lower limits of g_{A}, respectively. This function g_{A} (n) is shown not to depend on the quark confinement size (i.e. g_{A} is scale invariant), but only depends on the type of confinement (scalar, vector). Acceptable values for g_{A} are found with n_{s} = 23 (scalar) and n_{sv} = 0.50.7 (scalarvector).
 Publication:

Physics Letters B
 Pub Date:
 May 1986
 DOI:
 10.1016/03702693(86)908269
 Bibcode:
 1986PhLB..172..153T