Classical Nambu-Goldstone fields - art. no. 055003

It is shown that a Nambu-Goldstone (NG) field may be coherently produced by a large number of particles in spite of the fact that the NG bosuns do not couple to flavor conserving scalar densities such as <(psi)over bar>psi. I f a flavor oscillation process takes place, the phases of the pseudoscalar or flavor-violating densities of different particles do not necessarily can cel each other. The NG boson gets a macroscopic source whenever the total ( spontaneously broken) quantum number carried by the source particles suffer s a net increase or decrease in time. If the lepton numbers are spontaneous ly broken such classical NG (Majoron) fields may significantly change the n eutrino oscillation processes in stars, pushing the observational capabilit ies of neutrino-Majoron couplings down to m(nu)/300 GeV.