The L-R Correlator and its Chiral Condensates in the MHA and MHA+V' Approximations to Large-Nc QCD

In this talk, we describe part of a recent work on the correlation function of a V-A current with a V+A current in the framework of QCD in the limit of a large number of colours Nc. The discussion takes place within two successive approximations of this theory, called MHA and MHA+V'. Results concerning the evaluation of chiral condensates of dimension six and eight, as well as matrix elements of the Q7 and Q8 electroweak penguin operators, are given.