Related papers: $Z_c(3900)$ as a Four-Quark State
In this paper, we construct the axialvector and tensor current operators to investigate the ground state tetraquark states and the first radially excited tetraquark states with the quantum numbers $J^{PC}=1^{+-}$ via the QCD sum rules…
In this article, we tentatively assign the $Z_c^\pm(3900)$ to be the diquark-antidiquark type axialvector tetraquark state, study the hadronic coupling constants $G_{Z_cJ/\psi\pi}$, $G_{Z_c\eta_c\rho}$, $G_{Z_cD \bar{D}^{*}}$ with the QCD…
In this work, we systematically calculate the mass spectra of the $S$-wave fully heavy tetraquark states $bb\bar b\bar b$, $cc\bar c\bar c$, and $bb\bar c\bar c$ in two nonrelativistic quark models. A tetraquark state may be an admixture of…
In this article, we distinguish the charge conjunctions of the interpolating currents, calculate the contributions of the vacuum condensates up to dimension-10 in a consistent way in the operator product expansion, study the masses and pole…
In this article, we distinguish the charge conjugations of the interpolating currents, calculate the contributions of the vacuum condensates up to dimension-10 in the operator product expansion, and study the masses and pole residues of the…
Hadronic states composed of multi-quark flavors may exist in reality since they are not prohibited by QCD. Compact four quark systems of color singlet are classified as tetraquarks. To understand the properties of these states, more…
The mass spectra of light-heavy tetraquarks $cq\bar{c}\bar{q}$ (q= u, d) are computed in a non-relativistic diquark model with one-gluon exchange plus confining potential. In the diquark model, a $cq\bar{c}\bar{q}$ state is regarded to be…
Within the framework of QCD sum rules, we have investigated the tetraquark states with three heavy quarks. We systematically construct the interpolating currents for the possible $cc\bar{c}\bar{q}$, $cc\bar{b}\bar{q}$, $bc\bar{b}\bar{q}$,…
We use QCD sum rules to study the possible existence of a \Theta c(3250) charmed pentaquark. We consider the contributions of condensates up to dimension-10 and work at leading order in \alpha_s. We obtain m(\Theta c) = (3.21 +/- 0.13) GeV,…
The mass and meson-current coupling of the diquark-antidiquark states with the quantum numbers $J^{P}=0^{+}$ and quark contents $Z_{q}=[cq][\bar {b} \bar q ]$ and $Z_{s}=[cs][\bar {b} \bar s]$ are calculated using two-point QCD sum rule…
Motivated by the LHCb's very recent observation of exotic $X_{0}(2900)$ in the $B^{+}\rightarrow D^{+}D^{-}K^{+}$ process, for which could be a good open charm $ud\bar{c}\bar{s}$ tetraquark candidate, we endeavor to investigate its…
In this article, we assume the $Z_c(4200)$ as the color octet-octet type axial-vector molecule-like state, and construct the color octet-octet type axial-vector current to study its mass and width with the QCD sum rules. The numerical…
We study the internal structure of a range of four-quark states with charm quark contributions using a two-body Bethe-Salpeter equation. Thereby, we examine charmonium-like states with hidden charm and quark content $c\bar{c}q\bar{q}$,…
Within the diquark-antidiquark framework, this study investigates the masses of ground-state tetraquarks composed of heavy charm ($c$) and bottom ($b$) quarks and antiquarks, using the Bethe-Salpeter formalism. We establish the…
Stimulated by the newly observed charged hidden-charm state $Z_{cs}(3985)^-$ by BESIII Collaboration, $Z_{cs}(4000)^+$, $Z_{cs}(4220)^+$ and the excited $B_s^0$ states by LHCb Collaboration, a full calculation including masses and decay…
The mass, coupling and width of the newly observed charged resonance $ Z_{c}^{-}(4100)$ are calculated by treating it as a scalar four-quark system with a diquark-antidiquark structure. The mass and coupling of the state $ Z_{c}^{-}(4100)$…
Inspired by the recent report of the exotic states $X_{0}(2900)$ and $X_{1}(2900)$ with four different quark flavors in the $D^{-}K^{+}$ invariant mass distributions of the decay process $B^{+}\rightarrow D^{+}D^{-}K^{+}$ by the LHCb…
We continue our study of heavy-light four-quark states and find evidence from lattice QCD for the existence of a strong-interaction-stable $I(J^P)=0(1^+)$ $ud\bar{c}\bar{b}$ tetraquark with mass in the range of 15 to 61 MeV below…
It is demonstrated that the candidate tetraquark states $Z_b(10610)$, $Z_b(10650)$, $Z_c(3900)$, and $Z_c(4025)$ are coupled channel cusp effects. The model explains in a natural way the masses and quantum numbers of the putative states and…
In this work, we estimate the masses of tetraquark states with four different flavors by virtue of QCD sum rules, in both $b$ and $c$ sectors. We construct four $[8_c]_{\bar{b} s} \otimes [8_c]_{\bar{d} u}$ tetraquark currents with $J^P =…