Prediction of the anomalous magnetic moment of nucleon from the nucleon anomaly

Abstract

We construct the effective anomaly lagrangian involving nucleons and photons by using current-current coupling method. The contribution of this lagrangian to the anomalous magnetic moment of nucleon is purely isovector. The anomalous magnetic moment of proton, $κ_P$, can be calculated from the this lagrangian and it is found to be $κ_P^{Theor.} = 1.77$, which is in excellent agreement with the experimental value $κ_P^{Exp.} = 1.79$. While the case of neutron, $κ_N^{Theor.} = -2.58$ as compared to $κ_N^{Exp.} =-1.91$, is less satisfactory, but the sign is correct.