pISSN 0374-4914 eISSN 2289-0041

## Research Paper

New Physics: Sae Mulli 2010; 60: 648-652

Published online June 30, 2010 https://doi.org/10.3938/NPSM.60.648

## Mass of the Scalar Meson κ within a QCD Sum Rule

Hee Jung LEE*

Department of Physics Education, Chungbuk National University, Cheongju 361-763

Correspondence to:hjl@chungbuk.ac.kr

### Abstract

By using the QCD sum rule, we analyze the mass of the scalar meson κ, which has I = 1/2 in the scalar meson nonet of mass less than 1 GeV. The correlator for the meson is calculated under the assumption that the meson κ is in the tetraquark state consisting of a scalar diquarkantidiquark and an pseudoscalar diquark-antidiquark. From the QCD sum rule up to operators of
energy dimension 10 with instanton contributions, we show that the mass of the meson κ may be stable around 730 MeV when the two types of diquark-antidiquark have equal weights and phases.

Keywords: Scalar mesons, QCD sum rule, Diquark, Tetraquark, Instanton