Gamma ray bursts via emission of axion-like particles

The Pseudo-Goldstone Boson (PGB) emission could provide a very efficient mechanism for the cosmic Gamma Ray Bursts (GRBs). The PGBs produced in the merger of two neutron stars (or neutron star and black hole) can decay into e(+)e(-) and photons at distances of hundreds or thousands km, where the baryon density is low. In this way, a huge energy (up to 10(54) erg) can be deposited into an ultrarelativistic e(+)e(-) plasma, the fireball. For producing a successful GRBs, the PGB should have mass of older MeV, coupling to nucleons g(aN) similar to 10(-6) and to electrons g(ae) similar to 10(-9). Neither present experimental data nor astrophysical arguments can exclude such an ultramassive axion-like PGB. Our mechanism could also explain the association of some GRBs with supernovae type Ib/c and help the supernova type II explosion. (C) 2000 Published by Elsevier Science B.V. All rights reserved.