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arXiv 1004.4375hep-phnucl-th
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重离子碰撞中色超导夸克物质相的可及性

Accessibility of color superconducting quark matter phases in heavy-ion collisions

D. B. Blaschke, F. Sandin, V. V. Skokov, S. Typel

摘要:

我们讨论了一个混合状态方程(EoS),满足质量半径关系和冷却的紧凑型恒星的约束。夸克物质EoS是由色超导的Polyakov-loop Nambu-Jona-Lasinio(PNJL)模型得到的,强子物质EoS是由密度依赖耦合的相对论平均场(RMF)模型得到的.为了简化相变区的构造,我们在此采用麦克斯韦构造。本文给出了对称物质的相图,它具有两个显著的特点:(1)在T ~ 150 MeV以下,强子-夸克物质相界的“鼻子”结构随临界密度的增加而增加;(2)双色超导相界的高临界温度,T_c > 160 MeV。利用UrQMD程序计算了重离子碰撞在激发能-重子密度平面上的轨迹,并推测当入射能量为4. 8 A GeV,例如,通过JINR Dubna的Nuclotron-M或通过未来的重离子碰撞实验CBM@FAIR和NICA@JINR的最低能量,可以获得色超导夸克物质相。

英文摘要:

We discuss a hybrid equation of state (EoS) that fulfills constraints for mass-radius relationships and cooling of compact stars. The quark matter EoS is obtained from a Polyakov-loop Nambu--Jona-Lasinio (PNJL) model with color superconductivity, and the hadronic one from a relativistic mean-field (RMF) model with density-dependent couplings (DD-RMF). For the construction of the phase transition regions we employ here for simplicity a Maxwell construction. We present the phase diagram for symmetric matter which exhibits two remarkable features: (1) a "nose"-like structure of the hadronic-to-quark matter phase border with an increase of the critical density at temperatures below T ~ 150 MeV and (2) a high critical temperature for the border of the two-flavor color superconducting (2SC) phase, T_c > 160 MeV. We show the trajectories of heavy-ion collisions in the plane of excitation energy vs. baryon density calculated using the UrQMD code and conjecture that for incident energies of 4 ... 8 A GeV as provided, e.g., by the Nuclotron-M at JINR Dubna or by lowest energies at the future heavy-ion collision experiments CBM@FAIR and NICA@JINR, the color superconducting quark matter phase becomes accessible.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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