Showing papers by "Johan Bijnens published in 2008"

Quark Mass dependence at Two Loops for Meson Properties

Abstract: This talks contains a short introduction to Chiral Perturbation Theory and the existing calculations to two-loop order in the mesonic sector. I include a discussion on which quantities the expansion can be organized in. The present best values of the Low-Energy-Constants as determined from continuum physics are given as well as the assumptions underlying the fits to experimental data. I present plots of masses, decay constants and f+(0) in Kl3 as a function of quark or meson masses. The talk ends with a list of things for which it would be extremely useful to have good results from lattice QCD calculations

$\eta$ and $\eta'$ Physics

Abstract: This talk describes the reasons why $\eta$ and $\eta^\prime$ decays are an interesting topic of study for both theory and experiment. The main part discusses the results of the recent calculation of $\eta\to3\pi$ at two-loop order in ChPT. Some puzzling aspects of the results compared to earlier dispersive calculations are highlighted. I also like to remind the reader of the use of $\eta$ and $\eta^\prime$ decays for studying the anomaly.

Radiative and semileptonic decays in Chiral Perturbation Theory

Abstract: I give a short overview of what has been done in radiative and semileptonic Kaon decays in Chiral Perturbation Theory. This includes for semileptonic decays the work which has been done to order $p^6$ including preliminary results of isospin breaking to that order in $K_{\ell3}$. For the radiative decays I mainly present some results from recent work concerning $K_{\ell3\gamma}$.