Cluster reducibility of multiquark operators

Abstract

It is shown that the multiquark gauge-invariant operators can, in general, be decomposed into combinations of products of ordinary hadronic operators, exhibiting their cluster reducibility. The latter property inhibits the formation of completely compact multiquark bound states. Multiquark operators still play a crucial role in the description of exotic states in regions of configuration space where the hadronic clusters are close to each other. Our proof gives a foundation for a unified viewpoint, where the multiquark-type and the molecular-type approaches play complementary roles, at the gauge-invariant nonlocal operator level.

16 pages, 12 figures. A sentence has been changed in the abstract. A few minor changes in the main text

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Cited by in corpus (12)

• Hidden charm pentaquarks with color-octet substructure in QCD Sum Rules
• Tetraquarks in large-$N_c$ QCD
• Tetraquark-adequate QCD sum rules for quark-exchange processes
• The interplay between compact and molecular structures in tetraquarks
• 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
• Mission Target: Exotic Multiquark Hadrons -- Sharpened Blades
• Comment on "Landau equation and QCD sum rules for the tetraquark molecular states" [Phys. Rev. D 101, 074011 (2020)]
• Manifestation of Quantum Forces in Spacetime: Towards a General Theory of Quantum Forces
• Cluster Reducibility of Multiquark Operators and Tetraquark-Adequate QCD Sum Rules
• Meson scattering and tetraquarks in two-dimensional QCD
• Multiquark-Oriented QCD Sum Rules