5–10 GeV Neutrinos from Gamma-Ray Burst Fireballs

A gamma-ray burst fireball is likely to contain an admixture of neutrons. Inelastic collisions between differentially streaming protons and neutrons in the fireball produce ν_μ (ν_μ) of ~10GeV as well as νₑ (νₑ) of ~5GeV, which could produce ~7events/year in km³ detectors, if the neutron abundance is comparable to that of protons. Photons of ~10GeV from π⁰ decay and ~100MeV νₑ from neutron decay are also produced, but will be difficult to detect. Photons with energies 1MeV from shocks following neutron decay produce a characteristic signal which may be distinguishable from the proton-related MeV photons.