We numerically study the decay of cosmic global string loops due to radiation of Goldstone bosons and massive scalar (χ) particles. The length of loops we study range from 200 to 1000 times the width of the string core. We find that the lifetime of a loop is ≈1.4L. The energy spectrum of Goldstone boson radiation has a k-1 falloff, where k is the wave number, and a sharp peak at k≈mχ/2, where mχ is the mass of χ. The latter is a new feature and implies a peak at high energies (MeV-GeV) in the cosmological distribution of QCD axions.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)