WAVE-FUNCTION-INDEPENDENT RELATIONS BETWEEN THE NUCLEON AXIAL-COUPLING G(A) AND THE NUCLEON MAGNETIC-MOMENTS

We calculate the proton's magnetic moment mu(p) and its axial-vector coupling g(A) as a function of its Dirac radius R1 using a relativisitic three-quark model formulated on the light-cone. The relationship between mu(p) and g(A) is found to be independent of the assumed form of the light-cone wavefunction. At the physical radius R1 = 0.76 fm, one obtains the experimental values for both mu(p) and g(A), and the helicity carried by the valence u and d quarks are each reduced by a factor congruent-to 0.75 relative to their non-relativistic values. At large proton radius, mu(p) and g(A) are given by the usual non-relativistic formulae. At small radius, mu(p) becomes equal to the Dirac moment, as demanded by the Drell-Hearn-Gerasimov sum rule. In addition, as R1 --> 0, the constituent quark helicities become completely disoriented and g(A) --> 0.