Crossover equation of state based on color-molecular-dynamics

Yasutake, Nobutoshi*; Maruyama, Toshiki  

The equation of state for dense matter is studied with colour molecular dynamics, in which hadron matter and quark matter are automatically distinguished only from quark colour state. The quark-quark interactions are optimized to be consistent with saturation properties: symmetric energy, -parameter, and incompressibility around nuclear density. In the calculations, the degrees of freedom of colours are solved at each numerical step, although the flavours are fixed as up or down quarks. The resultant mass-radius relations of neutron stars also satisfy the observational constraints. In this model deconfined quark matter appears in the core of neutron stars via crossover. Although the current constraints from the observations are not enough to conclude whether quark matter appears at high-density region, our method would help to understand high-density material properties inside neutron stars.