Application of Bayesian statistics to the sector of decay constants in three-flavour χPT

The sector of decay constants of the octet of light pseudoscalar mesons in the framework of 'resummed' (3)SU(3) chiral perturbation theory is investigated. A theoretical prediction for the decay constant of eta-meson is compared to a range of available determinations. Compatibility of these determinations with the latest fits of the SU(3) low energy coupling constants is discussed. Using a Bayesian statistical approach, constraints on the low energy coupling constants L-4(r) and L-5 (R), as well as higher order remainders to the decay constants F-K and F-eta, are extracted from the most recent experimental and lattice QCD inputs for the values of the decay constants.