First-order phase boundaries of the massive ( 1+1 )-dimensional Nambu–Jona-Lasinio model with isospin
First-order phase boundaries of the massive (
1+1
)-dimensional Nambu–Jona-Lasinio model with isospin
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大量 (
DOI：
10.1103/physrevd.101.074013
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发表时间：
2020
影响因子：
5
通讯作者：
M. Thies
中科院分区：
文献类型：
--
作者：
M. Thies
在大 $N_c$ 限制下重新考虑具有同位旋 (isoNJL) 的大规模二维 Nambu--Jona-Lasinio 模型。我们通过构建缺失的一阶相边界继续探索其相图。在零温度下，重子和同位旋化学势平面中的相界将真空与晶相分开。我们从 isoNJL 模型的重子能谱中得出它，而 isoNJL 模型又是通过数值 Hartree-Fock (HF) 计算获得的。在有限温度下，使用热 HF 计算找到一阶相界片。它在零温相界和微扰片之间平滑插值。由于假设带电π介子凝聚物消失，计算仍然容易处理。在这种情况下，大部分计算可以使用过去开发的解决大规模单一风味 NJL 模型的方法来完成。
The massive two-dimensional Nambu--Jona-Lasinio model with isospin (isoNJL) is reconsidered in the large $N_c$ limit. We continue the exploration of its phase diagram by constructing missing first-order phase boundaries. At zero temperature, a phase boundary in the plane of baryon and isospin chemical potentials separates the vacuum from a crystal phase. We derive it from the baryon spectrum of the isoNJL model which, in turn, is obtained via a numerical Hartree-Fock (HF) calculation. At finite temperature, a first-order phase boundary sheet is found using a thermal HF calculation. It interpolates smoothly between the zero temperature phase boundary and the perturbative sheet. The calculations remain tractable owing to the assumption that the charged pion condensate vanishes. In that case, most of the calculations can be done with methods developed in the past for solving the massive one-flavor NJL model.