  In the formation process of black holes, the density and temperature of
matter become sufficiently high for quarks and pions to appear. In this study
we numerically investigate stellar core collapse and black hole formation
taking into account the equations of state involving quarks and/or pions. In
our simulations, we utilize a code that solves the general relativistic
hydrodynamics and neutrino transfer equations simultaneously, treating neutrino
reactions in detail under spherical symmetry. Initial models with three
different masses, namely, 40, 100 and 375Msolar, are adopted. Our results show
that quarks and pions shorten the duration of neutrino emission if the collapse
bounces before black hole formation. In addition, pions increase the luminosity
and average energy of neutrinos before black hole formation. We also find that
the hadron-quark phase transition leads to an interesting evolution of
temperature. Moreover, the neutrino event number is evaluated for the currently
operating neutrino detector, SuperKamiokande, to confirm that it is not only
detectable but also affected by the emergence of quarks and pions for Galactic
events. While there are some issues, such as hyperons, beyond the scope of this
study, this is the first serious attempt to assess the impact of quarks and
pions in dynamical simulations of black hole formation and will serve as an
important foundation for future studies.
