Related papers: Z_c(3900) - what is inside?
In the present work, the triply heavy tetraquarks states $QQ\bar{Q}\bar{q}$ with $Q=(c, b)$ and $q=(u, d, s)$ with all possible quantum numbers are systematically investigated in the framework of the chiral quark model with the resonance…
New data from BESIII and LHCb show the existence of resonances with strangeness filling multiplets of the broken SU(3)_f symmetry, with the pattern predicted by the quark model. This is the case of the newly discovered Z_{cs} (3985) and…
Flavor-exotic tetraquark mesons have recently been observed in the heavy-quark pair sectors of QCD, including two isospin multiplets in the b b-bar sector, Z_b(10610) and Z_b(10650), and one isospin multiplet in the c c-bar sector,…
Hadrons and their distributions are the most direct observables in experiment, which would shed light on the non-perturbative mystery of quantum chromodynamics (QCD). As the result, any new hadron will challenge our current knowlege on the…
To illustrate the campaign to understand heavy quarkonium systems, I focus on a puzzling new state, $X(3872) \to \pi^+\pi^- J/\psi$. Studying the influence of open-charm channels on charmonium properties leads us to propose a new charmonium…
In the quark model, hadrons are dominantly bound states of quark-antiquark pairs (mesons) or three quarks (baryons), but QCD also allows hadronic states to be composed of more quarks bound together. Recently, BESIII, Belle and LHCb have…
Exotic resonant structures found in $\Lambda^0_b$ and $\overline{B}^0$ decays into charmonium in the LHCb experiment are discussed. Examination of the $J/\psi p$ system in $\Lambda^0_b\to J/\psi K^- p$ decays shows two states each of which…
The relativistic four-quark equations with the open-charm and the open-strange are found in the framework of coupled-channel formalism. The dynamical mixing of the meson-meson states with the four-quark states is considered. The four-quark…
At the invariant mass spectrum of $h_c\pi^\pm$ a new resonance $Z_c(4020)$ has been observed, however the previously confirmed $Z_c(3900)$ does not show up at this channel. In this paper we assume that $Z_c(3900)$ and $Z_c(4020)$ are…
We discuss the charge conjugation quantum number for tetraquarks or meson-meson molecules, seen as possible interpretations of the newly found $XYZ$ charmonium-like resonances.
A discussion is presented of the estimates of the energy and width of resonances in constituent models, with focus on the tetraquark states containing heavy quarks.
We use a non-relativistic model to study the spectroscopy of a tetraquark composed of $[cc][\bar{c}\bar{c}]$ in a diquark-antidiquark configuration. By numerically solving the Schr\"{o}dinger equation with a Cornell-inspired potential, we…
Recently the LHCb experiment found evidence for the existence of two exotic resonances consisting of $c\bar{c}uud$ quarks. Among the possible interpretations is the hadro-charmonium model, in which charmonium is bound "within" a light…
The newly reported exotic signal $Z_c(4100)$ by the LHCb Collaboration in the invariant mass spectrum of $\eta_c\pi^-$ in $B^0\to \eta_c K^+ \pi^-$ has been a new experimental evidence for an exotic meson containing four constituent quarks.…
We present a plausible mechanism for the origin of the $XYZ$ mesons in the heavy meson spectra within a standard quark-model picture. We discuss the conditions required for the existence of four--quark bound states or resonances…
The strange pentaquarks with hidden heavy quark pair ($q^3c\bar c$ and $q^3b \bar b$) are investigated by the coupled-channel quark cluster model. Two types of the $q^3$ color-octet configurations are found to provide the attraction, which…
We identify the recently observed charmonium-like structure $Z_c^\pm(3900)$ as the charged partner of the X(3872) state. Using standard techniques of QCD sum rules, we evaluate the three-point function and extract the coupling constants of…
The recent confirmation of the charged charmonium like resonance Z(4430) by the LHCb experiment strongly suggests the existence of QCD multi quarks bound states. Some preliminary results about hypothetical flavored tetraquark mesons are…
In the present work we investigate the $\eta_c K$, $J/\psi K$, $\eta_c K^*$ and $J/\psi K^*$ hidden-charm decay modes for the $c\bar{c}s\bar{u}$ four-quark system in the molecular and compact tetraquark scenarios using the quark-exchange…
In the framework of a nonrelativistic chiral quark model, we continue to study the mass spectra of the fully-heavy $bb\bar{c}\bar{c}$ and $bc\bar{b}\bar{c}$ tetraquarks. In the present calculations, two structures, meson-meson…