Two Topics in QCD Sum-Rules: Bounds on Light Quark and Scalar Gluonium Masses

Abstract

QCD Laplace sum-rules are briefly reviewed and two sum-rule applications are presented. For scalar gluonium, upper bounds on the lightest state are obtained from ratios of Laplace sum-rules, and the role of instantons and the low-energy theorem on these bounds is investigated. For the light-quark masses, fundamental inequalities for Laplace sum-rules are developed, which lead to a lower bound on the average of the up and down quark masses.

Latex2e, 17 pages. Write-up of talk presented at Ochanomizu high-energy physics workshop