Rotation induced charged pion condensation in a strong magnetic field: A Nambu–Jona-Lasino model study
Rotation induced charged pion condensation in a strong magnetic field: A Nambu–Jona-Lasino model study
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强磁场中旋转引起的带电π介子凝聚：Nambu-Jona-Lasino 模型研究
DOI：
10.1103/physrevd.100.094015
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发表时间：
2019
影响因子：
5
通讯作者：
Lianyi He
中科院分区：
文献类型：
--
作者：
Gaoqing Cao;Lianyi He
在以夸克为基本自由度的Nambu-Jona-Lasinio模型中，研究了平行转动和磁场存在下带电π介子凝聚的可能性.以前基于无相互作用的Klein-Gordon理论的研究表明，在这种情况下，带电π介子将发生玻色-爱因斯坦凝聚[Y。刘和我。Zahed，Phys. Rev. Lett. 120，032001（2018）。在这项工作中，我们考虑到内部夸克结构的带电π介子自洽通过夸克极化环的相互作用理论，即，南武-乔纳-拉西诺模型系统对带电π介子凝聚形成的稳定性，即，探讨了复合带电π介子场μ i γ5d的一个非零期望值。我们发现转动引起了两种相互竞争的效应：有利于带电π凝聚的同位旋增强和不利于带电π凝聚的自旋破缺。在强磁场（eB = 1 GeV^2）和几个费米的系统尺寸下，同位旋增强效应比自旋破缺效应更强，带电的π凝聚在超过几MeV的临界角速度时变得更有利。
We investigate the possibility of charged pion condensation in the presence of parallel rotation and magnetic field within the Nambu–Jona-Lasinio model with quarks as the fundamental degrees of freedom. Previous study based on noninteracting Klein-Gordon theory for pions showed that the charged pions will.undergo Bose-Einstein condensation under this circumstance [Y. Liu and I. Zahed, Phys. Rev. Lett. 120, 032001 (2018).]. In this work, we take into account the internal quark structures of charged pions selfconsistently through quark polarization loops in an interacting theory, i.e., the Nambu–Jona-Lasino model..The stability of the system against the formation of charged pion condensation, i.e., a nonzero expectation value of the composite charged pion field ¯uiγ5d, is explored. We find that two competing effects are induced by the rotation: the isospin enhancement which favors charged pion condensation and the spin.breaking which disfavors the condensation. For a strong magnetic field (eB ∼ 1 GeV^2) and system size of a few fermi, the isospin enhancement effect is stronger than the spin breaking one, and the charged pion condensation becomes energetically favored beyond a critical angular velocity of a few MeV.