出版社：SISSA, Scuola Internazionale Superiore di Studi Avanzati
摘要：We consider the physics of neutrinos in a fireball, i.e. a tightly coupled plasma of photons,
positrons and electrons. Such a fireball is believed to form in the first stages of a gamma-ray burst.
We assume the fireball is radiation-dominated and spherically symmetric. Energy considerations
limit the allowed baryon density, from which it follows that the neutrino physics is dominated by
leptonic processes. We find that, for quite general initial conditions, neutrinos start out in thermodynamic
equilibrium with the fireball and follow the usual hydrodynamical evolution. As the
fireball cools, the plasma becomes transparent to neutrinos which subsequently decouple from the
plasma. Although a sizable fraction of the total energy is carried away, the detection possibility
of these neutrino bursts is limited due to the isotropic outflow and the relatively low mean energy
of approximately 60 MeV.
