Chiral-symmetry restoration in the Nambu-Jona-Lasinio model with a constant electromagnetic field.
Chiral-symmetry restoration in the Nambu-Jona-Lasinio model with a constant electromagnetic field.
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DOI：
10.1103/physrevd.39.3478
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发表时间：
1989-06
期刊：
影响因子：
--
通讯作者：
S. Klevansky;R. H. Lemmer
中科院分区：
文献类型：
--
作者：
S. Klevansky;R. H. Lemmer
固有时Schwinger形式在由Nambu—Jona-Lasinio模型描述的与恒定电磁场最小耦合的相互作用费米子系统的间隙方程和总能量的推导中实现。包含一个拉格朗日乘子项来改变标量密度，可以计算能量曲线作为标量密度的函数，而标量密度起着序参数的作用。在计算总能量和间隙关系时，实现了该理论中出现的发散量的一致规范不变和洛伦兹不变正则化。专门研究恒定电场，我们发现在电场的临界值处可以发生手性对称性恢复相变。对于我们选择的参数，/ital g/…/一口2 / / 2π…/sup 2/=1.12 and .lambda..=1041 MeV，得到动态生成质量/ m//sub /ital E/=0//sup */=208 MeV，临界场/ital eE//sub /ital c//=(270 MeV)/sup 2/。相反，恒定磁场通过稳定手性断真空态来抑制相变。
The proper-time Schwinger formalism is implemented in a derivation of the gap equation and total energy of a system of interacting fermions described by the Nambu--Jona-Lasinio model that is minimally coupled to a constant electromagnetic field. Inclusion of a Lagrange multiplier term to vary the scalar density enables the calculation of energy curves as a function of the scalar density that plays the role of an order parameter. A consistent gauge- and Lorentz-invariant regularization of the divergent quantities that occur in this theory is implemented in calculating the total energy and gap relation. Specializing to constant electric fields, we find that a chiral-symmetry-restoration phase transition can occur at a critical value of the electric field. For our choice of parameters, /ital g/..lambda../sup 2//2..pi../sup 2/=1.12 and ..lambda..=1041 MeV, one finds the dynamically generated mass /ital m//sub /ital E/=0//sup */=208 MeV and critical field /ital eE//sub /ital c//=(270 MeV)/sup 2/. By contrast, aconstant magnetic field is found to inhibit the phase transition by stabilizingthe chirally broken vacuum state.