Chiral condensates, Q7 and Q8 matrix elements and large-Nc QCD -: art. no. 043

The correlation function of a V - A current with a V + A current is discussed within the framework of QCD in the limit of a large number of colours N-c. Applications to the evaluation of chiral condensates of dimension six and higher, as well as to the matrix elements of the Q(7) and Q(8) electroweak penguin operators are discussed. A critical comparison with previous determinations of the same parameters has also been made.