Instanton interpolating current for $\sigma$--tetraquark

Abstract

We perform a QCD sum rule analysis for the light scalar meson $\sigma$ ($f_0(600)$) with a tetraquark current related to the instanton picture for QCD vacuum. We demonstrate that instanton current, including equal weights of scalar and pseudoscalar diquark-antidiquarks, leads to a strong cancelation between the contributions of high dimension operators in the operator product expansion (OPE). Furthermore, in the case of this current direct instanton contributions do not spoil the sum rules. Our calculation, obtained from the OPE up to dimension 10 operators, gives the mass of $\sigma$--meson around 780MeV.

11 pages, 7 figures, final version to be appeared in Phys. Lett. B

References in corpus (3)

• Scalar Mesons a0(1450) and sigma(600) from Lattice QCD
• Large next-to-leading order QCD corrections to pentaquark sum rules
• The Riddle of the f0(980) and a0(980): Are They the Quark-Antiquark States?

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