Tetraquark-adequate QCD sum rules for quark-exchange processes

Abstract

We consider quark-hadron duality relations and QCD sum rules for correlators involving exotic tetraquark currents, here specializing to the case of quark-exchange processes. We point out the differences they exhibit with respect to the cases involving ordinary bilinear quark currents. Based on the observation that only diagrams possessing at least four-quark singularities can contribute to the formation of tetraquark states, we show that the quark-hadron duality relations and the corresponding sum rules split into two non-overlapping relations. The ultimate tetraquark-adequate QCD sum rule is concerned only with one of these relations, in which the operator product expansion starts with diagrams of order $O({\alpha }_s^2)$.

8 pages, version to appear in Phys. Rev. D

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• Multiquark Resonances
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• Are There Tetraquarks at Large $N_c$ in QCD(F)?
• Narrow exotic tetraquark mesons in large-$N_c$ QCD
• Tetraquark-adequate formulation of QCD sum rules
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Cited by in corpus (5)

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• OPE and quark-hadron duality for two-point functions of tetraquark currents in $1/N_c$ expansion
• Multiquark-Adequate QCD Sum Rules: the Case of Flavour-Exotic Tetraquarks
• Comment on "Landau equation and QCD sum rules for the tetraquark molecular states" [Phys. Rev. D 101, 074011 (2020)]
• Multiquark-Oriented QCD Sum Rules