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arXiv · hep-ph/0309158

Instantons and Scalar Multiquark States: From Small to Large N_c

Thomas Schaefer
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Abstract

We study scalar quark-anti-quark and two-quark-two-anti-quark correlation functions in the instanton liquid model. We show that the instanton liquid supports a light scalar-isoscalar (sigma) meson, and that this state is strongly coupled to both $(\bar{q}q)$ and $(\bar{q}q)^2$. The scalar-isovector $a_0$ meson, on the other hand, is heavy. We also show that these properties are specific to QCD with three colors. In the large $N_c$ limit the scalar-isoscalar meson is not light, and it is mainly coupled to $(\bar{q}q)$.

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Thomas Schaefer. 2003-09-14. Instantons and Scalar Multiquark States: From Small to Large N_c. https://doi.org/10.1103/physrevd.68.114017

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