Search for the charmed baryonium and dibaryon structures via the QCD sum rules

Abstract

In the present work, we construct eight six-quark currents to study the Σc Σc baryonium and ΣcΣc dibaryon states via the QCD sum rules. For either Σc Σc baryonium or ΣcΣc dibaryon states, we construct four currents with the J P = 1 − , 1 + , 0 + and 0 − . Except the current 1 + of ΣcΣc, we find the Borel windows for the other seven. There are two possible Σc Σc molecular states or compact six-quark states with the J P = 1 − and 0 − . The results of the current 0 + of ΣcΣc show a possible ΣcΣc molecular state with 20 MeV binding energy. We find two Σc Σc baryonium resonances states with the J P = 1 + , 0 + and two ΣcΣc dibaryon resonances states with the J P = 0 − , 1 − , respectively. Pole residues of the seven states are also calculated.

Triply-charmed hexaquark states with the QCD sum rules

“…In previous works, we construct the color-singlet-color-singlet type (color-singlet-color-singletcolor-singlet type) six-quark currents to explore the triply-heavy dibaryon (hexaquark molecular) states and doubly-heavy dibaryon states with the QCD sum rules [26,27,28] ( [29]), and construct the diquark-diquark-diquark type six-quark currents to explore the triply-heavy hexaquark state [30]. In all the works [26,27,28,29,30], there are explicit light degrees of freedom in the six-quark currents, the contributions from the valence light quarks are very large.…”

Chiral perturbation theory for heavy hadrons and chiral effective field theory for heavy hadronic molecules

“…In 2017, the LHCb Collaboration reported the Ξ ++ cc in the Λ + c K − π + π + decay mode [173] and one year later in the Ξ + c π + decay mode [174]. Its mass is [175] m Ξ ++ cc = 3621.55 ± 0.23 (stat) ± 0.30 (syst) MeV, (10) and its lifetime [176] is τ = (2.56 ± 0.27) × 10 −13 s. (11) There have been extensive theoretical efforts to study the mass spectrum, the strong decay patterns, the electromagnetic properties, the life time and other properties of the doubly heavy baryon in different frameworks, such as the bag models [177,178,179,180], various quark models [181,182,183,184,185,108,77], Bethe-Salpeter equation [186], Born-Oppenheimer EFT [187,188], the Regge phenomenology [189,190], QCD sum rule [191,192,193,194,195,196,159], heavy diquark effective theory [197], and lattice QCD [131,145,146].…”