Electromagnetic corrections for pions and kaons: Masses and polarizabilities

The unknown constants in Chiral Perturbation Theory needed for an all orders analysis of the polarizabilities and electromagnetic corrections to the masses of the pseudo-Goldstone bosons are estimated at leading order in 1/N-c. We organize the calculation in an 1/N-c expansion and separate long- and short-distance physics contributions by introducing a Euclidean cut-off: The long-distance part is evaluated using the ENJL model and the short-distance part using perturbative QCD and factorization. We obtain very good matching between both. We then include these estimates in a full chiral perturbation theory calculation to order e(2)p(2) for the masses and p(6) for the polarizabilities. For the electromagnetic corrections to the masses, we confirm a large violation of Dashen's theorem getting a more precise value for this violation. We make a comparison with earlier related work, Some phenomenological consequences are discussed too. (C) 1997 Elsevier Science B.V.