The (Polyakov) Nambu‐ Jona‐Lasinio (PNJL) approach is an effective theory for low energies which shares with Quantumchromodynamics (QCD) the global symmetries. This approach is easy to handle and allows for analytical results for many of the observables which are of interest for the studies of ultrarelativistic heavy‐ion collisions but also for the merger and collisions of neutron stars. It allows in particular to study the density and temperature dependence of quark masses and of the masses of mesons and baryons as well as the chiral phase transition. In recent times, this transition came in the focus of interest because it is expected that the upcoming experiments at the Fair (Germany) and NICA (Russia) facilities will observe a Quark‐Gluon‐Plasma (QGP) at finite baryon chemical potential. In this contribution, we show that the extended PNJL model is able to describe the properties of symmetric matter at vanishing chemical potential, as determined by lQCD calculations.

中文翻译：

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在扩展的Polyakov Nambu Jona-Lasinio Lagrangian的关键端点和一阶相变中

（Polyakov）Nambu-Jona-Lasinio（PNJL）方法是一种有效的低能理论，与量子色动力学（QCD）具有全局对称性。这种方法易于操作，并且可以为许多可观测的观测结果提供分析结果，这对于研究超相对论重离子碰撞以及中子星的合并和碰撞都很有意义。它尤其允许研究夸克质量以及介子和重子质量的密度和温度依赖性以及手性相变。近年来，这种转变成为人们关注的焦点，因为预计即将在Fair（德国）和NICA（俄罗斯）设施进行的实验将观察到具有有限重子化学势的Quark-Gluon-Plasma（QGP）。在这笔捐款中，