论文标题
$π$ - $ a_1 $混合和低能定理的分辨率对角线化
Gauge-covariant diagonalization of $π$-$a_1$ mixing and the resolution of a low energy theorem
论文作者
论文摘要
使用最近提出的量规协方差对角线$πa_1$ - 混合我们表明，低能定理$ f^π= ef_π^2 f^2 f^{3π} $的当前代数的$因子$ f_ {π^0 \toγγ} = f^π$，在Nambu-Jona-Lasinio（NJL）模型的框架中实现，解决了包括向量和轴向矢量介子在内的扩展中遇到的长期存在的问题。解决方案的核心是存在$γπ{\ bar q} Q $顶点，该顶点在对角度化的常规处理中不存在，并导致偏离矢量介子介导（VMD）图片的偏差。它有助于规范不变的三轴（AAA）顶点作为纯表面项。
Using a recently proposed gauge covariant diagonalization of $πa_1$-mixing we show that the low energy theorem $F^π=e f_π^2 F^{3π}$ of current algebra, relating the anomalous form factor $F_{γ\to π^+π^0π^-} = F^{3π}$ and the anomalous neutral pion form factor $F_{π^0 \to γγ}=F^π$, is fulfilled in the framework of the Nambu-Jona-Lasinio (NJL) model, solving a long standing problem encountered in the extension including vector and axial-vector mesons. At the heart of the solution is the presence of a $γπ{\bar q} q $ vertex which is absent in the conventional treatment of diagonalization and leads to a deviation from the vector meson dominance (VMD) picture. It contributes to a gauge invariant anomalous tri-axial (AAA) vertex as a pure surface term.
