Holder inequalities and isospin splitting of the quark scalar mesons

A Holder inequality analysis of the QCD Laplace sum rule which probes the n on-strange (n (n) over bar) components of the I = {0,1} (light-quark) scala r mesons supports the methodological consistency of an effective continuum contribution from instanton effects, This revised formulation enhances the magnitude of the instanton contributions which split the degeneracy between the I = 0 and I-I channels. Despite this enhanced isospin splitting effect , analysis of the Laplace and finite-energy sum rules seems to preclude ide ntification of either a(0)(980) or a light broad sigma-resonance as states with predominant n (n) over bar components, in which case their dominant co mponents could then be meson-meson (pi pi or Kkr), multiquark, or glueball states. This apparent decoupling of sigma[ = f(0)(400-1200)] and a(0)(980) from the quark n (n) over bar scalar currents suggests the possible identif ication of the f(0)(980) and a(0)(1450) as the lightest I = (0,1) scaler me sons in which the n (n) over bar component is dominant. (C) 2000 Elsevier S cience B.V. All rights reserved.