Is the exotic X(5568) a bound state?

Chen, Xiaoyun; Ping, J. L.

doi:10.1140/epjc/s10052-016-4210-x

Cited by 53 publications

(54 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…considering as ∆-∆ structure and the corresponding mass was given. Chen et al gave an explicit QCD sum rule investigation for hidden-charm baryonium states with various relevant local interpreting currents, and they found some of these currents can couple to hidden-charm baryonium states with the masses around 5.0 GeV [25]. Ref.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Hidden-bottom and -charm hexaquark states in QCD sum rules

2020

View full text Add to dashboard Cite

In this paper, we investigate the spectra of the prospective hidden-bottom and -charm hexaquark states with quantum numbers J P C = 0 ++ , 0 −+ , 1 ++ and 1 −− in the framework of QCD sum rules.By constructing appropriate interpreting currents, the QCD sum rules analyses are performed up to dimension 12 of the condensates. Results indicate that there exist two possible baryonium states in b-quark sector with masses 11.84 ± 0.22 GeV and 11.72 ± 0.26 GeV for 0 ++ and 1 −− , respectively. The corresponding hidden-charm partners are found lying respectively at 5.19 ± 0.24 GeV and 4.78 ± 0.23GeV. Note that these baryonium states are all above the dibaryon thresholds, which enables their dominant decay modes could be measured at BESIII, BELLEII, and LHCb detectors. * wanbingdong16@mails.ucas.ac.cn † tangl@hebtu.edu.cn ‡ qiaocf@ucas.ac.cn, corresponding author Hadrons with more than the minimal quark content (qq or qqq) was proposed by Gell-Mann [1] and Zweig [2] in 1964, which were named as multiquark exotic states and do not infringe the Quantum Chromodynamics (QCD). Exploring the existence and properties of such exotic states is one of the most intriguing research topics of hadronic physics. In past few decades, research on the heavy-flavor exotic states has made tremendous developments, that is, many charmonium-like/bottomonium-like XYZ states have been observed [3-7]. In 2015, two hidden-charm pentaquarks P c (4380) and P c (4450) [8] were observed by the LHCb Collaboration in the J/ψ invariant mass spectrum via the Λ 0 b → J/ψpK − process. Recently, the LHCb Collaboration reported a new narrow state P c (4312), and the previously observed structure P c (4450) appears to be split into two narrower structures P c (4440) and P c (4457) [9].The recent experimental and theoretical progresses can be found in comprehensive reviews like [10][11][12][13][14].Facing the observations of tetraquark and pentaquark states, it is nature to conjecture that there should exist the hidden-charm and -bottom hexaquark states, and it is time to hunt for them. For the hexaquark states, the deuteron is a typical and well-established dibaryon molecular state with J P = 1 + and binding energy E B = 2.225MeV [15]. The baryonium states composed of a baryon and an anti-baryon is another special class of heaxquark configuration. In Refs. [16,17], the Λ c -Λ c structure was introduced to explain the production and decays of Y (4260). And the heavy baryonium was explored as well in the heavy baryon chiral perturbation theory [18,19].The method of QCD sum rules [20][21][22][23] has been applied successfully to many hadronic phenoemena, such as the hadron spectrum and hadron decays. In QCD sum rules, based on the proper interpreting currents corresponding to a hadron of interest, one can construct the two-point or three-point correlation functions, which are respectively used to evaluate the mass and the decay property of the related hadron. Then by matching its operator product expansion (OPE) to its hadronic saturation, the main function for ext...

show abstract

Section: Introductionmentioning

confidence: 99%

“…Then by matching its operator product expansion (OPE) to its hadronic saturation, the main function for extracting the mass or decay rate of the hadron is established. Utilizing this approach, several significant researches for the hexaquark states have been done [24][25][26][27][28]. In Ref.[24], six-quark state d * (2380) was…”

mentioning

confidence: 99%

Hidden-bottom and -charm hexaquark states in QCD sum rules

2020

View full text Add to dashboard Cite

show abstract

“…For instance, the difficulty to accommodate such a narrow struca e-mail: lisheng.geng@buaa.edu.cn ture with a relatively low mass has been stressed by Burns et al [17] and Guo et al [18]. A recent study in the chiral quark model showed that neither diquark-antidiquark nor meson-meson structures support the existence of X (5568) [19]. In Ref.…”

Section: Introductionmentioning

confidence: 99%

$$B_s\pi $$ B s π – $$B\bar{K}$$ B K ¯ interactions in finite volume and X(5568)

Ren

Geng

2017

Eur. Phys. J. C

View full text Add to dashboard Cite

The recent observation of X (5568) by the D0 Collaboration has aroused a lot of interest both theoretically and experimentally. In the present work, we first point out that X (5568) and D * s0 (2317) cannot simultaneously be of molecular nature, from the perspective of heavy-quark symmetry and chiral symmetry, based on a previous study of the lattice QCD scattering lengths of DK and its coupled channels. Then we compute the discrete energy levels of the B s π and BK system in finite volume using unitary chiral perturbation theory. The comparison with the latest lattice QCD simulation, which disfavors the existence of X (5568), supports our picture where the B s π and BK interactions are weak and X (5568) cannot be a B s π and BK molecular state. In addition, we show that the extended Weinberg compositeness condition also indicates that X (5568) cannot be a molecular state made from B s π and BK interactions.

show abstract

“…It has a mass of 5619.5 MeV, it is lighter than the mass of b , so that X (5568) seems not to be a subd tetraquark, if it indeed exists. The other researches [29][30][31] support the idea that such a tetraquark with constituents of subd should be heavier than b .…”

Section: Introductionmentioning

confidence: 86%

The possible $$B\pi $$ B π molecular state and its radiative decay

Gao

2017

Eur. Phys. J. C

View full text Add to dashboard Cite

Recently, several exotic bosons have been confirmed as multi-quark states. However, there are violent disputes about their inner structures, namely if they are molecular states or tetraquarks, or even mixtures of the two structures. It would be interesting to search experimentally for non-strange four-quark states with open charm or bottom which are lighter than c or b . Reasonable arguments indicate that they are good candidates of pure molecular states Dπ or Bπ because pions are the lightest boson. Both Bπ and Dπ bound states do not decay via the strong interaction. The Bπ molecule may decay into B * by radiating a photon, whereas the Dπ molecule can only decay via weak interaction. In this paper we explore the mass spectra of the Bπ molecular states by solving the corresponding instantaneous B-S equation. Then the rate of radiative decay | 3 2 , 1 2 → B * γ is calculated and our numerical results indicate that the processes can be measured by the future experiment. We also briefly discuss the Dπ case. Due to the constraint of the final state phase space it can only decay via weak interaction.

show abstract

Is the exotic X(5568) a bound state?

Cited by 53 publications

References 25 publications

Hidden-bottom and -charm hexaquark states in QCD sum rules

Hidden-bottom and -charm hexaquark states in QCD sum rules

$$B_s\pi $$ B s π – $$B\bar{K}$$ B K ¯ interactions in finite volume and X(5568)

The possible $$B\pi $$ B π molecular state and its radiative decay

Contact Info

Product

Resources

About