Zero-locus diagnostic of the direct contact term in $\varphi \to {\pi }^{+}{\pi }^{-}{\pi }^0$

Seung-il Nam, Jung Keun Ahn

We formulate, within a fixed FSI-improved amplitude convention, a zero-locus diagnostic for the direct contact term in $\varphi \to {\pi }^{+}{\pi }^{-}{\pi }^0$. The resonant $\rho \pi$ contribution is dressed ch…