Application of Bayesian statistics to the sector of decay constants in three-flavour $$\chi $$PT

Abstract

AbstractThe sector of decay constants of the octet of light pseudoscalar mesons in the framework of ‘resummed’ SU(3) chiral perturbation theory is investigated. A theoretical prediction for the decay constant of $$\eta $$ η -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 $$L_4^r$$ L 4 r and $$L_5^r$$ L 5 r , as well as higher order remainders to the decay constants $$F_K$$ F K and $$F_\eta $$ F η , are extracted from the most recent experimental and lattice QCD inputs for the values of the decay constants.