Astrophysical constraints on the couplings of axions, majorons, and familons

The spontaneous breaking of a global symmetry leads to the existence of Nambu-Goldstone bosons which, through their coupling to electrons and/or photons, can transport energy from the cores of stars and affect significantly the course of stellar evolution. We find by following in detail the evolution of stars that if the couplings to electrons and/or photons is too strong, helium never ignites—in contradiction with the observational evidence. Our limits restrict the axion mass to less than 0.01 eV, the familon breaking scale to >7×${10}^9$ Gev, and the triplet majoron vacuum expectation value to <9 keV.