Chiral Structure of Scalar and Pseudoscalar Mesons

We systematically study the chiral structure of local tetraquark currents of flavor singlet and J(p) = 0(+). We also investigate their chiral partners, including scalar and pseudoscalar tetraquark currents of flavor singlet, octet, 10, (10) over bar, and 27. We study their chiral transformation properties. Particularly, we use the tetraquark currents belonging to the nonexotic [((3) over bar, 3)circle plus(3, (3) over bar)] chiral multiplets to calculate the masses of light scalar mesons through QCD sum rule. The two-point correlation functions are calculated including all terms and only the connected parts (Weinberg (2013), Coleman (1985), and Page (2003)). The results are consistent with the experimental values.