Recently, the dynamics and neutrino emission of a black-hole forming stellar collapse is suggested to depend crucially on the equation of state (EOS). In such a case, density and temperature of the matter may become enough high to occur a deconfinement transition of hadronic matter to quark matter. In this study, we perform the gravitational collapse of massive stars using an EOS with the hadron-quark phase transition for finite temperature. In the computations, neutrino transfer equations are solved simultaneously with general relativistic hydrodynamics under spherical symmetry. A progenitor model with 40 solar masses (M⊙) is adopted as the initial condition of the collapse. This model has already been shown to produce a bounce before black hole formation. We find that, in this process, the interval time from the bounce to the black hole formation becomes shorter because the transition makes EOS softer. We also find a somewhat unfamiliar decrease of temperature throughout the transition. The event number of neutrinos emitted from our model is evaluated for the currently operating neutrino detector, SuperKamiokandeIII (SK III). As a result, the total neutrino event number becomes smaller due to the transition. We implied that the sign of the quark appearance can be distinguished by the total event number and energy spectrum.
|Journal||Proceedings of Science|
|Publication status||Published - Dec 1 2008|
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