论文标题
手性旋转对称性和热/密集QCD
Chiral spin symmetry and hot/dense QCD
论文作者
论文摘要
在T_ {CH} 〜155 MEV周围的手性对称性恢复上方的QCD中出现了新的机制，该方案是一种刺激的流体，其特征在于热分区功能的近似手性旋转对称性。这种对称不是Dirac Lagrangian的对称性，并且是QCD Lagrangian电动部分的对称性。在此制度中，培养基由手性对称和近似手性的自旋对称的黑龙组成，这些黑龙是由通过限制的染色场连接到彩色单曲线化合物的手性对称夸克制成的。该机制可以通过空间和时间相关因子的近似手性旋转对称性以及在〜3 t_ {ch}派对上的跨界（Quark-gluon等离子体）和严格的流体方案之间的交叉扰动理论的分解。手性旋转对称性平稳地消失在〜3t_ {ch}上方，这意味着要筛选染色体限制相互作用。直接证据表明，刺激的流体培养基由密集的载火子组成，是倾斜光谱函数，显示出明显的锥度状态，其第一个径向激发在t_ {ch}上方。在弦液中的强子自由度的另一个直接证据是底元光谱具有1S，2S，3S和1P，2P径向和轨道激发，它们随温度而变宽。 T_ {CH}和〜3 T_ {CH}之间的HADRON在弦流中的相互作用很强，这使得丝状流体更多地是液体而不是气体。我们讨论这种手性自旋对称状态如何扩展到有限的化学电位域，并提供QCD相图的定性草图。
Above the chiral symmetry restoration crossover around T_{ch} ~ 155 MeV a new regime arises in QCD, a stringy fluid, which is characterized by an approximate chiral spin symmetry of the thermal partition function. This symmetry is not a symmetry of the Dirac Lagrangian and is a symmetry of the electric part of the QCD Lagrangian. In this regime the medium consists of the chirally symmetric and approximately chiral spin symmetric hadrons that are made of the chirally symmetric quarks connected into the color singlet compounds by a confining chromoelectric field. This regime is evidenced by the approximate chiral spin symmetry of the spatial and temporal correlators and by the breakdown of the thermal perturbation theory at the crossover between the partonic (the quark-gluon plasma) and stringy fluid regimes at ~ 3 T_{ch}. The chiral spin symmetry smoothly disappears above ~ 3T_{ch} which means that the chromoelectric confining interaction gets screened. A direct evidence that the stringy fluid medium consists of densely packed hadrons is the pion spectral function that shows a distinct pion state and its first radial excitation above T_{ch}. Another direct evidence of the hadron degrees of freedom in the stringy fluid is the bottomonium spectrum with the 1S,2S,3S and 1P,2P radial and orbital excitations that become broad with temperature. The hadrons between T_{ch} and ~ 3 T_{ch} in the stringy fluid interact strongly which makes the stringy fluid more a liquid rather than a gas. We discuss how this chiral spin symmetric regime extends into the finite chemical potentials domain and present a qualitative sketch of the QCD phase diagram.
