Related papers: Four-quark state in QCD
The mass spectra of ground-state triply heavy baryons are systematically unscrambled and computed in QCD sum rules. With a tentative $(QQ)-(Q')$ configuration for $QQQ'$, the interpolating currents representing the triply heavy baryons are…
Study of the spectrum and structure of color non-singlet combinations of quarks and antiquarks, neutralized by a non-dynamical compensating color source, may provide an interesting way to address questions about QCD that cannot be addressed…
We estimate the mass of the pentaquark state with QCD sum rules and find that pentaquark states with isospin $I=0, 1, 2$ lie close to each other around $(1.55\pm 0.15)$ GeV. The experimentally observed baryon resonance $\Theta^+ (1540)$…
The possibility of $QQ\bar{q}\bar{q}$ heavy-light four-quark bound states has been analyzed by means of the chiral SU(3) quark model, where $Q$ is the heavy quark ($c$ or $b$) and $q$ is the light quark ($u$, $d$ or $s$). We obtain a bound…
Four-quark states with different internal clusters are discussed within the constituent quark model. It is pointed out that the diquark concept is not meaningful in the construction of a tetraquark interpolating current in the QCD sum rule…
$QQ^\prime qq\bar q$ pentaquarks are studied in a potential model, under the hypothesis that they are composite objects of two diquarks and one antiquark. The interaction between two colored objects includes two contributions, one based on…
In the present work, we construct the diquark-antidiquark type four-quark currents to investigate the mass spectrum of the ground state hidden-charm-hidden-strange tetraquark states with the quantum numbers $J^{PC}=0^{++}$, $1^{+-}$,…
Very recently, the LHCb Collaboration observed distinct structures with the $cc\bar{c}\bar{c}$ in the $J/\Psi$-pair mass spectrum. In this work, we construct four scalar ($J^{PC} = 0^{++}$) $[8_c]_{Q\bar{Q^\prime}}\otimes [8_c]_{Q^\prime…
After constructing the possible $J^P=0^-, 0^+, 1^-$ and $1^+$ $QQ\bar{q}\bar{q}$ tetraquark interpolating currents in a systematic way, we investigate the two-point correlation functions and extract the corresponding masses with the QCD sum…
Masses for $\{Q\bar{q}\}\{\bar{Q}^{(')}q\}$ molecular states are systematically studied in QCD sum rules. The interpolating currents representing the related molecular states are proposed. Technically, contributions of the operators up to…
Light and heavy pentaquarks are described within a constituent quark model based on a spin-flavor hyperfine interaction. In this model the lowest state acquires positive parity. The masses of the light antidecuplet members are calculated…
Many of the $XYZ$ resonances observed by the Belle, Babar, CLEO and BESIII collaborations in the past decade are difficult to interpret as conventional quark-antiquark mesons, motivating the consideration of scenarios such as multi-quark…
In this article, we construct the charmed-diquark-charmed-diquark-charmed-diquark type current to study the axialvector triply-charmed hexaquark state with the QCD sum rules in details. In calculations, we take the energy scale formula…
We present a study of the effect of charm quarks on the QCD equation of state using partially-quenched p4 charm quarks on a dynamically generated 2+1 flavor background, at zero chemical potential. We show preliminary results for the charm…
QCD sum rule is applied to the pentaquark spectroscopy. It is concluded that no positive parity state is seen in low energy region, while there may exist negative parity states at around 1.5 GeV. Choice of interpolating local operators and…
In this work, we construct the color $\bar{\mathbf{3}}\bar{\mathbf{3}}\bar{\mathbf{3}}$ type local five-quark currents with the light quarks $qss$ in the flavor octet, and study the $qssc\bar{c}$ pentaquark states via the QCD sum rules in a…
In the article, we investigate the diquark-diquark-antiquark type fully-heavy pentaquark states with the spin-parity $J^P={\frac{1}{2}}^-$ via the QCD sum rules, and obtain the masses $M_{cccc\bar{c}}=7.93\pm 0.15\,\rm{GeV}$ and…
The QCD quark cyclobutadiene (ring-like), a new color structure of tetraquark system, is proposed and studied in the flux tube model with multi-body confinement potential. The QCD quark cyclobutadiene and other flux tube structures of…
We present results of a lattice calculation of tetraquark states with quark contents $q_1q_2\bar{Q}\bar{Q}, \, q_1,q_2 \subset u,d,s,c$ and $Q \equiv b,c$ in both spin zero ($J=0$) and spin one ($J=1$) sectors. These calculations are…
In this work, we present a systematic calculation of the mass spectrum for tetraquark hybrid states, focusing on the $8_{[c\bar{c}]}\otimes 8_{[G]}\otimes 8_{[c\bar{c}]}$ color configuration, within the framework of QCD sum rules. As an…