Weinberg sum rules at NLO in 1/Nc

Abstract

We study the relevance of different renormalization schemes in Resonance Chiral Theory. The SS-PP correlator is explicitly computed at the one-loop level. Demanding the operator product expansion behaviour at short distances produces a new set of constraints, as some logarithmic terms are absent at high energies. Likewise, the loops induce subleading corrections in 1/Nc to the leading-order constraints, the Weinberg sum rules. We find that the short-distance conditions from a minimally subtracted scheme generate large uncertainties which, alternatively, can be largely simplified in other schemes.

Comments: 4 pages, to appear in the Proceedings of the conference Chiral Dynamics, Bern, 6-10 July 2009. PoS style