While the QCD Lagrangian as the whole is only chirally symmetric, its electric part has larger chiral-spin SU(2)CS and SU(2NF) symmetries. This allows separation of the electric and magnetic interactions in a given reference frame. Artificial truncation of the near-zero modes of the Dirac operator results in the emergence of the SU(2)CS and SU(2NF) symmetries in hadron spectrum. This implies that while the confining electric interaction is distributed among all modes of the Dirac operator, the magnetic interaction is located at least predominantly in the near-zero modes. Given this observation one could anticipate that above the pseudocritical temperature, where the near-zero modes of the Dirac operator are suppressed, QCD is SU(2)CS and SU(2NF) symmetric, which means absence of deconfinement in this regime. Solution of the NF = 2 QCD on the lattice with a chirally symmetric Dirac operator reveals that indeed in the interval Tc − 3Tc QCD is approximately SU(2)CS and SU(2NF) symmetric which implies that degrees of freedom are chirally symmetric quarks bound by the chromoelectric field into color-singlet objects without the chromomagnetic effects. This regime is referred to as a Stringy Fluid. At larger temperatures this emergent symmetry smoothly disappears and QCD approaches the Quark–Gluon Plasma regime with quasifree quarks. The Hadron Gas, the Stringy Fluid and the Quark–Gluon Plasma differ by symmetries, degrees of freedom and properties.

中文翻译：

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QCD的三种制度

虽然 QCD 拉格朗日整体只是手征对称，但其电学部分具有较大的手征自旋小号ü(2)CS和小号ü(2ñF)对称性。这允许在给定的参考系中分离电和磁相互作用。Dirac算子的近零模态的人为截断导致出现小号ü(2)CS和小号ü(2ñF)强子谱的对称性。这意味着虽然限制电相互作用分布在狄拉克算子的所有模式中，但磁相互作用至少主要位于接近零的模式中。鉴于这一观察，我们可以预期在伪临界温度之上，狄拉克算子的近零模式被抑制，QCD 是小号ü(2)CS和小号ü(2ñF)对称的，这意味着该制度中没有解除限制。的解决方案ñF = 2具有手性对称狄拉克算子的晶格上的 QCD 揭示了确实在区间吨C - 3吨CQCD 约为小号ü(2)CS和小号ü(2ñF)对称，这意味着自由度是手性对称的夸克，被色电场束缚成没有色磁效应的单色物体。这种状态被称为粘性流体。在更高的温度下，这种出现的对称性会平稳地消失，并且 QCD 接近具有准自由夸克的夸克-胶子等离子体状态。强子气体、粘性流体和夸克-胶子等离子体在对称性、自由度和性质方面有所不同。