Decay constants of pseudoscalar mesons to two loops in three-flavor partially quenched chiral perturbation theory -: art. no. 094502

This paper presents a first study of the decay constants of the charged, or flavor-off-diagonal, pseudoscalar mesons to two loops for three flavors of sea quarks, in partially quenched chiral perturbation theory (PQ chi PT). Explicit analytical expressions up to O(p(6)) in the momentum expansion are given. The calculations have been performed within the supersymmetric formulation of PQ chi PT. We also present some numerical results to indicate the size of the corrections.