Analysis of Y (4660) and Related Bound States with QCD Sum Rules

Abstract

In this article, we take the vector charmonium-like state Y (4660) as a Ψ' f0 (980) bound state (irrespective of the hadro-charmonium and the molecular state) tentatively, and study its mass using the QCD sum rules. The numerical value MY = 4.71±0.26 GeV is consistent with the experimental data. Considering the SU(3) symmetry of the light flavor quarks and the heavy quark symmetry, we also study the bound states Ψ'σ (400–1200), γ‴ f0 (980), and γ‴ σ (400–1200) with the QCD sum rules, and make reasonable predictions for their masses.