QCD SUM-RULES AND THE PI(1300) RESONANCE

Global fits to the shape of the first QCD Laplace sum rule exhibiting sensitivity to pion-resonance [Pi(1300)] parameters are performed, lea ding to predictions for the pion-resonance mass and decay constant. Tw o scenarios are considered which differ only in their treatment of the dimension-six quark condensate [O-6]. The first scenario assumes an e ffective scale for [O-6] from other sum-rule applications which is ass umed to be independent of the physical value of the quark mass, while the second scenario requires self-consistency between the value of [O- 6] and the current algebra constraint 2m[(q) over bar q] = - f(pi)(2)m (pi)(2). Predictions of the pion-resonance mass M-pi and decay constan t F-pi are obtained in these two scenarios. A byproduct of this analys is is a prediction of the renormalization-group invariant quark mass ( (m) over cap(u) + (m) over cap(d))/2. (C) 1997 Elsevier Science B.V.