Gaussian sum-rules and prediction of resonance properties

Techniques For using Gaussian QCD sum-rules to predict hadronic resonance properties are developed fur single-resonance and two-resonance phenomenological models, and criteria are developed fur determining which of these models is required for analyzing a particular hadronic channel. The vector current sum-rule coupled to the rho meson is shown to be consistent with a single resonance model, and the Gaussian sum-rule analysis results in an accurate rho mass prediction which exhibits excellent agreement between the theoretical prediction of the Gaussian sum-rule and the phenomenological model. A two-resonance model is shown to be necessary for the Gaussian sum-rule for the nonstrange quark scalar (lin) currents. The two-resonance Gaussian sum-rule analysis of the isoscalar and isovector (I = 0, 1) nn scalar mesons exhibits excellent agreement between the theoretical prediction and phenomenological model. The prediction of the resonance properties of the I = 0, 1 (n) over barn scalar mesons in this two-resonance model provides valuable information for the interpretation of the scaler mesons, including the X(1775). (C) 2001 Elsevier Science B.V. All rights reserved.