Decays of the neutral and long-lived η and η′ mesons provide a unique, flavor-conserving
laboratory to test low-energy Quantum Chromodynamics and search for new physics …

In this work we study the axial contributions to the hadronic light-by-light piece of the muon
anomalous magnetic moment. We point out some theoretical ambiguities in previous …

Within a dispersive approach to hadronic light-by-light scattering in the muon g-2, the
evaluation of the numerically dominant pseudoscalar-pole contribution involves the …

The recent measured γ* γ→ π 0 transition form factor in the spacelike region by the Belle
Collaboration together with the previously published results by CLEO, CELLO, and BABAR …

The η′ transition form factor is reanalyzed in view of the recent first observation by BESIII of
the Dalitz decay η′→ γ e+ e-in both space-and timelike regions at low and intermediate …

The η and η′ transition form factors in the spacelike region are analyzed at low and
intermediate energies in a model-independent way through the use of rational …

The η η transition form factor is analyzed for the first time in both space-and time-like regions
at low and intermediate energies in a model-independent approach through the use of …

The description of the VV′ P form factors (V, V′ stands for vector particles and P for a
pseudoscalar meson) for different particles virtualities remains a challenge for the theory of …

A bstract We have studied the P→ γ⋆ γ⋆ transition form-factors (P= π 0, η, η′) within a
chiral invariant framework that allows us to relate the three form-factors and evaluate the …

We perform a comparative theoretical study of the data at spacelike momentum transfer for
the<? format?> γ* γ→ π 0 transition form factor, just reported by the Belle Collaboration, vs …