Structure of flavor changing Goldstone boson interactions

A bstract General flavor changing Goldstone boson (GB) interactions with fermions from a spontaneous global U(1) G symmetry breaking are discussed. This GB may be the Axion, solving strong QCD CP problem, if there is anomaly for assignments of quarks charge. Or it Majoron, producing seesaw Majorana neutrino masses by lepton number violation, scale much higher than electroweak scale. It also, in principle, play roles Axion and Majoron simultaneously as far providing solution problem generating small concerned. Great attentions have been focused on conserving interactions. Recently models studied hope to find new physics rare decays intensity frontier. In this work, we will provide systematic model building aspect study neutral current (FCNC) fermion sectors, or separately quark, charged sectors identify detail sources FCNC class beyond standard breaking. We also general proof equivalence using physical components broken generators calculating couplings two gluons photons, discuss some issues related violation models. Besides, details obtaining several popular models, such Type-I, -II, -III Left-Right symmetric point out special features these