Related papers: Z_c(3900) - what is inside?
Inspired by the experimentally reported $T_{c\bar{s}}(2900)$ exotic states, the $S$-wave $\bar{q}q\bar{s}Q$ $(q=u,\,d;\,Q=c,\,b)$ tetraquarks, with spin-parity $J^P=0^+$, $1^+$ and $2^+$, in both isoscalar and isovector sectors are…
The XYZ mesons are unexpected mesons containing a heavy quark-antiquark pair that have been discovered during the last decade. The models for the XYZ mesons that have been proposed include conventional quarkonium, quarkonium hybrids, and…
The masses of tetraquark states of all $qc\bar q \bar c$ and $cc\bar c \bar c$ quark configurations are evaluated in a constituent quark model, where the Cornell-like potential and one-gluon exchange spin-spin coupling are employed. All…
We investigate the nature of the recently observed narrow resonance $Z_{c}(3900)$, which is assumed to be a $D^{*}\bar{D}$ molecular state with quantum numbers $I^{G}J^{P}=1^{+}1^{+}$. Using QCD sum rules, we consider contributions up to…
We use a non-relativistic model to study the mass spectroscopy of a tetraquark composed by $c \, \bar{c} \, c \, \bar{c}$ quarks in the diquark-antidiquark picture. By numerically solving the Schr\"{o}dinger equation with a Cornell-inspired…
In order to test different models proposed for some states discovered recently in the charmonium mass range that do not fit into the pattern predicted by the conventional quark model, we derive predictions for the spectrum within the…
In the diquark-diantiquark composition, we study the masses of hidden charm tetraquark systems ($cq\bar{c}\bar{q}$, $cs\bar{c}\bar{s}$ and $cs\bar{c}\bar{q}$) using a linear confinement potential. In this study, we have factorized the four…
A new charged state, called $Z_c(3900)$ has been recently observed by BESIII collaboration in $J/\psi\pi^{\pm}$ channel. The same has been confirmed by Belle (called Z(3894.5 in the Belle paper). In this short note we discuss probable…
We consider the recently suggested model for some resonances near the open charm threshold as bound states of charmonium inside excited light mesons. It is argued in the soft-wall holographic model of QCD that such states of heavy…
Several methods for studying the nature of a resonance are applied to resonances recently discovered in the bottonomium and charmonium sectors. We employ the effective-range expansion, the saturation of the width and compositeness of a…
In the framework of color flux-tube model with a four-body confinement potential, the lowest charged tetraquark states $[Qq][\bar{Q}'\bar{q}']~(Q=c,b,q=u,d,s)$ are studied by using the variational method, Gaussian expansion method. The…
The LHCb Collaboration at the Large Hadron Collider at CERN discovered two pentaquark states $P_c(4380)$ and $P_c(4450)$. These two hidden-charm states are interpreted as the loosely bound $\Sigma_c(2455)D^*$ and $\Sigma_c^*(2520)D^*$…
Employing the relativized quark model and the quark-interchange model, we investigate the decay of the charged heavy quarkonium-like states $Z_c(3900)$, $Z_c(4020)$, $Z_c(4430)$, $Z_b(10610)$ and $Z_b(10650)$ into the ground and radially…
An interesting controversy has emerged challenging the widely accepted nature of the $X(3915)$ and the $X(3930)$ resonances, which had initially been assigned to the $\chi_{c0}(2P)$ and $\chi_{c2}(2P)$ $c\bar c$ states, respectively. To…
Quantum Chromodynamics presents a series of exact and approximate symmetries which can be exploited to predict new hadrons from previously known ones. The $Z_c(3900)$ and $Z_c(4020)$ resonances, which have been theorized to be isovector…
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…
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…
The low-lying $S$-wave $QQ\bar{s}\bar{s}$ ($Q=c, b$) tetraquark states with $IJ^P=00^+$, $01^+$ and $02^+$ are systematically investigated in the framework of complex scaling range of chiral quark model. Every structure including…
The LHCb collaboration has recently announced the discovery of two hidden-charm pentaquark states with also strange quark content, $P_{cs}(4338)$ and $P_{cs}(4459)$; its analysis points towards having both hadrons isospin equal to zero and…
We introduce the hypothesis that diquarks and antidiquarks in tetraquarks are separated by a potential barrier. We show that this notion can answer satisfactorily long standing questions challenging the diquark-antidiquark model of exotic…