Finite-size effects at the hadron-quark transition and heavy hybrid stars

ハドロン-クォーク相転移における有限サイズ効果と重いハイブリッド星

安武 伸俊*; Lastowiecki, R.*; Benic, S.*; Blaschke, D.*; 丸山 敏毅  ; 巽 敏隆*

Yasutake, Nobutoshi*; Lastowiecki, R.*; Benic, S.*; Blaschke, D.*; Maruyama, Toshiki; Tatsumi, Toshitaka*

We study the role of finite-size effects at the hadron-quark phase transition in a new hybrid equation of state constructed from an ab initio Brckner-Hartree-Fock theory, with the realistic Bonn-B potential for the hadronic phase and a covariant nonlocal Nambu-Jona-Lasinio model for the quark phase. We construct static hybrid star sequences and find that our model can support stable hybrid stars with an onset of quark matter below and a maximum mass above in agreement with recent observations. If the finite-size effects are taken into account the core is composed of pure quark matter. Provided that the quark vector channel interaction is small and the finite size effects are taken into account, quark matter appears at densities 2-3 times the nuclear saturation density. In that case the proton fraction in the hadronic phase remains below the value required by the onset of the direct URCA process, so that the early onset of quark matter shall affect on the rapid cooling of the star.