  It is shown that a gravitationally collapsing black hole acts as an ultrahigh
energy particle accelerator that can accelerate particles to energies
inconceivable in any terrestrial particle accelerator, and that when the energy
E of the particles comprising the matter in the black hole is $ \sim 10^{2} $
GeV or more,or equivalently the temperature T is $ \sim 10^{15}$ K or more, the
entire matter in the black hole will be in the form of quark-gluon plasma
permeated by leptons.
