Recent QCD-related results from kaon physics at CERN (NA48/2 and NA62)

The NA48/2 experiment presents a preliminary result of $K^{\pm}_{l}$ decays form factors measurement based on the $4.28 \times 10^{6} K^{\pm}_{e3}$ and $2.91 \times 10^{6} K^{\pm}_{\mu 3}$ selected decays collected in 2004. The result is competetive with other measurements in $K^{\pm}_{\mu 3}$ mode and has a smallest uncertainty for $K^{\pm}_{e3}$ , that leads to the most precise combined $K^{\pm}_{l3}$ and allows to reduce the form factor uncertainty of $\left | V_{US} \right |$. The NA62 experiment collected a large sample of charged kaon decays with a highly efficient trigger for decays into electrons in 2007. A final result of a new measurement of the electromagnetic transition form factor slope of the neutral pion in the time-like momentum region from the $1.11 \times 10^6$ fully reconstructed $\pi^{0}$ Dalitz decays is presented in the second part of this article.