2006 Fiscal Year Final Research Report Summary
Supernova Matter Equation of State Table Based on Heavy-Ion Collisions and Hypernuclear Reactions
| Project/Area Number |
15540243
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Particle/Nuclear/Cosmic ray/Astro physics
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| Research Institution | Hokkaido University |
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Principal Investigator |
OHNISHI Akira Hokkaido University, Faculty of Science, Associate Professor (70250412)
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| Co-Investigator(Kenkyū-buntansha) |
SUMIYOSHI Kohsuke Hokkaido University, Numazu College of Technology, Associate Professor (30280720)
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| Project Period (FY) |
2003 – 2006
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| Keywords | Supernova Explosion / Equation of State / Strangeness / Relativistic Mean Field (RMF) / Chiral Symmetry / High-Energy Heavy-Ion Collisions / Hydrodynamical Simulation / Black Hole Formation |
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| Research Abstract |
Nuclear matter properties at various temperatures and densities are expected to affect crucially supernova explosion and black hole formation processes. In this project, we aimed at constructing an equation of state (EOS) and nuclear distribution table for the use of supernova simulations based on heavy-ion collision and hypernuclear reactions. We also aimed at understanding the mechanism of supernova explosion and black hole formation by using the newly constructed supernova matter EOS table.
For heavy-ion collisions, we have developed a hadron transport model (JAM-RQMD/S) for high-energy heavy-ion collisions. In this model, the nuclear mean field is included as well as hadron-hadron collisions. We have shown that collective flows are reasonably well explained in a wide energy range (1~160A GeV) with momentum-dependent nuclear mean field. At RHIC enengy, we have compared the results of hydrodynamical model assuming QGP and hadron transport model, suggesting the formation of QGP even in
… More
lighter system (Cu+Cu). In addition, we have proposed a new hadronization mechanism.
In hypernuclear physics, we have analyzed the hyperon production spectra in bound and continuum energy region, and extracted the hyperon potentials in nuclear matter. It is found that potentials forΣand〓are more repulsive than those previously expected. We have also developed a chiral symmetric relativistic mean field model (Chiral RMF) based on the strong coupling lattice QCD.
In low density supernova matter, we have compared the EOSs in Nuclear Statistical Equilibrium (NSE) model and the Thomas-Fermi model with RMF. In order to connect these EOSs smoothly, we may need to consider pasta nuclei.
Based on these updated information, we have developed new EOS tables of supernova matter, and opened them to public. Since hyperon potentials are more repulsive than expected before, hyperons are suppressed in neutron star core. We also found that density and temperature are not high enough for hyperons to appear in supernova explosions, but that hyperons modifies the neutrino signal of black hole formation. Less
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