# XIIth Quark Confinement and the Hadron Spectrum

28 August 2016 to 4 September 2016
Europe/Athens timezone

## Electromagnetic transition form factor and radiative corrections in decays of neutral pions

29 Aug 2016, 19:30
20m
Aristotelis II (Makedonia Palace)

### Aristotelis II

#### Makedonia Palace

Section B: Light Quarks

### Speaker

Mr Tomas Husek (Charles University (CZ))

### Description

In this talk we present the Two-hadron saturation (THS) scenario for the PVV correlator and apply it to two important processes of the low energy hadron physics: the Dalitz decay of $\pi^0$ and $\pi^0\to e^+e^-$. We briefly summarize experimental and theoretical results on the rare decay $\pi^0\to e^+e^-$. The notorious $3.3\,\sigma$ discrepancy between the SM prediction and the experimental value provided by KTeV collaboration is discussed in the view of a complete set of NLO QED radiative corrections. The important contribution of analytical two-loop QED corrections together with the bremsstrahlung contribution beyond the soft-photon approximation are reviewed. Using the leading logarithm approximation, the possible contribution of QCD corrections is estimated. The discrepancy under discussion then reduces down to $1.8\,\sigma$. The obtained results can be also used in a theoretical calculation of the hadronic light-by-light scattering contribution to the $g-2$ type experiments.

### Primary authors

Dr Jiri Novotny (Charles University (CZ)) Dr Karol Kampf (Charles University (CZ)) Prof. Stefan Leupold (Uppsala University (SE)) Mr Tomas Husek (Charles University (CZ))