$\eta$ and ${\eta }^{\prime }$ transition form factors from Padé approximants

Abstract

We employ a systematic and model-independent method to extract, from space- and time-like data, the $\eta$ and ${\eta }^{\prime }$ transition form factors (TFFs) obtaining the most precise determination for their low-energy parameters and discuss the ${\Gamma }_{\eta \to \gamma \gamma }$ impact on them. Using TFF data alone, we also extract the $\eta -{\eta }^{\prime }$ mixing parameters, which are compatible to those obtained from more sophisticated and input-demanding procedures.

Comments: 4 pages, 2 figures, presented at the 13th International Workshop on Meson Production, Properties and Interaction (MESON 2014); added references