Gaussian sum-rules and prediction of resonance properties

Techniques For using Gaussian QCD sum-rules to predict hadronic resonance p roperties are developed fur single-resonance and two-resonance phenomenolog ical models, and criteria are developed fur determining which of these mode ls is required for analyzing a particular hadronic channel. The vector curr ent sum-rule coupled to the rho meson is shown to be consistent with a sing le resonance model, and the Gaussian sum-rule analysis results in an accura te rho mass prediction which exhibits excellent agreement between the theor etical prediction of the Gaussian sum-rule and the phenomenological model. A two-resonance model is shown to be necessary for the Gaussian sum-rule fo r the nonstrange quark scalar (lin) currents. The two-resonance Gaussian su m-rule analysis of the isoscalar and isovector (I = 0, 1) nn scalar mesons exhibits excellent agreement between the theoretical prediction and phenome nological 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(17 75). (C) 2001 Elsevier Science B.V. All rights reserved.