Table 3.

Combined fit to several pion VFF data sets (BaBar, KLOE, CMD-2, SND) and ${\eta }^{\prime }\to {\pi }^{+}{\pi }^{-}\gamma$ spectrum (BESIII) with overall ${\chi }^2/\text{dof}=1.64$. In the row for KLOE, the three values for $M_{\omega }$ refer to the combinations of the global KLOE $\omega$ mass and the corresponding mass shifts of the three underlying data sets from 2008, 2010, 2012, respectively. See main text for details