A New Approach to Weak Amplitudes in Large-Nc QCD
Abstract
We report on some recent progress made in understanding weak matrix elements of mesons in the context of the next-to-leading order of the large-Nc approximation to QCD. Specifically, we first use the example of the weak contributions to the pi^+ - pi^0 mass difference to exhibit how a systematic matching can be achieved analytically between short distances and long distances within our large-Nc framework. We are then also able to compute matrix elements of the operator Q_7, as they turn out to depend on the same QCD correlator as the previous pion mass difference. As a final example we determine the chiral counterterms governing the pseudoscalar decay into a lepton pair, where we briefly comment also on the special case K_L -> mu^+ mu^-.
Keywords
Cite
@article{arxiv.hep-ph/9910396,
title = {A New Approach to Weak Amplitudes in Large-Nc QCD},
author = {M. Knecht and S. Peris and E. de Rafael and .},
journal= {arXiv preprint arXiv:hep-ph/9910396},
year = {2008}
}
Comments
15 pages, 4 figures. LateX. This report covers the material presented by the authors in three separate talks at the QCD'99 conference in Montpellier