Chiral effective Lagrangian in the large-N-c limit: The nonet case

A U-L(3) X U-R(3) low-energy effective lagrangian for the nonet of pseudo-Goldstone bosons that appear in the large N-c limit of QCD is presented including terms up to four derivatives and explicit symmetry breaking terms up to quadratic in the quark masses. The one-loop renormalization of the couplings is worked out using the heat-kernel technique and dimensional renormalization. The calculation is carried through for U-L(n(l)) X U-R(n(l)), thus allowing for a generic number n(l) of light quark flavours. The crucial advantages that the expansion in powers of 1/N-c bring about are discussed. Special emphasis is put on pointing out what features are at variance with the SUL X SUR results when the singlet eta' is included in the theory. (C) 1997 Elsevier Science B.V.