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Maruyama, Toshiki; Chiba, Satoshi; Schulze, H.-J.*; Tatsumi, Toshitaka*
Journal of Physics G; Nuclear and Particle Physics, 35(10), p.104076_1 - 104076_4, 2008/10
Times Cited Count：3 Percentile：28.52(Physics, Nuclear)We investigate the property of the hadron-quark mixed phase using the Brueckner-Hartree-Fock model for hadron (hyperon) phase and the MIT bag model for quark phase. To satisfy the Gibbs conditions, charge density as well as baryon number density becomes non-uniform in the mixed phase. Taking into account the density distribution and the Coulomb interaction in a self-consistent way, we clarify the roles of the surface tension and the charge screening effect. We will show that the screened Coulomb interaction makes the EOS similar to the one given by the Maxwell construction. We demonstrate that hyperons are suppressed in the mixed phase, because hadron phase is positively charged. This is a novel mechanism of hyperon suppression in compact stars. Finally we will discuss some consequences of our EOS on the structure and the maximum mass of NS.
Maruyama, Toshiki; Chiba, Satoshi; Schulze, H.-J.*; Tatsumi, Toshitaka*
Exotic States of Nuclear Matter, p.290 - 297, 2008/02
Quark matter has been expected inside compact stars. Since the deconfinement transition from hadron to quark phase may occur as a first-order phase transition, the hadron-quark mixed phase should appear, where charge density as well as baryon number density is no more uniform. Owing to the interplay of the Coulomb interaction and the surface tension, the mixed phase can have an exotic shape called pasta structure. In a series of recent papers we have revealed an important role of the charge screening effect in the mixed phase. In this presentation, we incorporate a realistic EOS of hadronic matter which properly includes hyperon degree of freedom and discuss the properties of hadron-quark mixed phase in compact stars. Taking into account the charge screening effects on pasta structures of hyperon-quark mixed phase, we find that the resultant EOS is not so different from that given by the Maxwell construction (MC). Thereby the bulk properties of compact stars such as the mass-radius relation are little affected, compared with the MC case. However, the internal properties of the mixed phase are very different in two cases, especially about hyperons: hyperons always appear in the mixed phase in the MC case, while no hyperon in our case. Non-uniform structure and suppression of hyperons in the mixed phase should have some implications on the neutrino transport and cooling of pulsars as well as the maximum mass problem.
Maruyama, Toshiki; Chiba, Satoshi; Schulze, H.-J.*; Tatsumi, Toshitaka*
Physics Letters B, 659(1-2), p.192 - 196, 2008/01
Times Cited Count：40 Percentile：87.62(Astronomy & Astrophysics)no abstracts in English
Maruyama, Toshiki; Chiba, Satoshi; Schulze, H.-J.*; Tatsumi, Toshitaka*
Nuclear Physics A, 805, p.588 - 590, 2008/00
no abstracts in English
Maruyama, Toshiki; Chiba, Satoshi; Schulze, H.-J.*; Tatsumi, Toshitaka*
Physical Review D, 76(12), p.123015_1 - 123015_12, 2007/12
Times Cited Count：124 Percentile：96.31(Astronomy & Astrophysics)We analyze the different possibilities for the hadron-quark phase transition occurring in beta-stable matter including hyperons in neutron stars. We use a Brueckner-Hartree-Fock approach including hyperons for the hadronic equation of state and a generalized MIT bag model for the quark part. We then point out in detail the differences between Maxwell and Gibbs phase transition constructions including the effects of surface tension and electromagnetic screening. We find only a small influence on the maximum neutron star mass, whereas the radius of the star and in particular its internal structure are more affected.
Maruyama, Toshiki; Tatsumi, Toshitaka*; Schulze, H.-J.*; Chiba, Satoshi
no journal, ,
no abstracts in English
Maruyama, Toshiki; Tatsumi, Toshitaka*; Schulze, H.-J.*; Chiba, Satoshi
no journal, ,
no abstracts in English
Yasutake, Nobutoshi*; Maruyama, Toshiki; Tatsumi, Toshitaka*; Schulze, H.-J.*; Burgio, F. G.*
no journal, ,
We have calculated equation of state (EOS) of quark-hadron mixed phase in supernovae with finite temperature and neutrinos. To get EOS of matter with more than one chemical components, the Maxwell construction can not be applied but the Gibbs conditions should be fully considered. However, the resulting EOS of mixed phase with "pasta" structures are found to be close to that obtained with the Maxwell construction. We have found that in the mixed phase hyperons are suppressed by the negatively charged quark phase. We also found that the mixed phase becomes unstable by the temperature and trapped neutrinos. The resultant EOS of the mixed phase is found to be stiff as neutron star matter and soft as supernova matter, which is useful to get supernova explosions by simulations, and easy to satisfy maximum masses of neutron star observations.
Pikuz, S. Jr.*; Wagenaars, E.*; Culfa, O.*; Dance, R.*; Rossall, A.*; Tallents, G.*; Faenov, A.*; K
mpfer, T.*; Schulze, K.*; Uschmann, I.*; et al.
no journal, ,
W/cm
Faenov, A.*; Colgan, J.*; Abdallah, J. Jr.*; Pikuz, S. A.*; Wagenaars, E.*; Booth, N.*; Brown, C. R. D.*; Culfa, O.*; Dance, R.*; Evans, R.*; et al.
no journal, ,
