Abstract

The problem of spontaneous isotopic symmetry breaking in Nambu–Jona-Lasinio quark models is considered. It is shown that, in models with light quarks, isotopic symmetry remains unbroken. This property of Nambu–Jona-Lasinio models may likely be considered an explanation for the existence of isotopic symmetry in nature.

中文翻译：

---

Nambu-Jona-Lasinio模型的自发同位素对称性破裂问题

摘要

考虑了Nambu–Jona-Lasinio夸克模型中自发同位素对称性破裂的问题。结果表明，在具有轻夸克的模型中，同位素对称性保持不变。Nambu–Jona-Lasinio模型的这一特性可能被认为是自然界中存在同位素对称性的一种解释。