BOSON FERMION AND FERMION BOSON TRANSMUTATIONS INDUCED BY SUPERGRAVITY BACKGROUNDS IN SUPERSTRING THEORY

We investigate the physical implications and particle content of superstring scattering in the supergravity shock-wave background recently found by us. The amplitudes for the different particle transmutation processes taking place in this geometry are explicitly computed for Green-Schwarz superstrings, including the new phenomena of fermion to boson and boson to fermion transmutations. Transition amplitudes among the ground states, first and second excited states are obtained. Particularly interesting are the amplitudes within the massless particle sector, which lead to physical massive particles upon supersymmetry breaking at low energies.