Related papers: Understanding close-lying exotic charmonia states …

We study the exotic $\Delta^{0}\Delta^{0}$ dibaryon state with quantum numbers $J^{P} = 2^{+}$ within the framework of QCD sum rules. A tensor interpolating current is constructed to determine the mass and residue of this state, including…

We study the $DDK$ system in a coupled channel approach, by including $DD_s\eta$ and $DD_s\pi$, and find that the dynamics involved in the system forms a bound state with isospin $1/2$ and mass $4140$ MeV when one of the $DK$ pair is…

We present a coupled channel unitary approach to obtain states dynamically generated from the meson baryon interaction with hidden charm, using constraints of heavy quark spin symmetry. We use as basis of states, $\bar D B$, $\bar D^* B$…

We apply the method of QCD sum rules to study the $s s \bar s \bar s$ tetraquark states of $J^{PC} = 0^{-+}$. We construct all the relevant $s s \bar s \bar s$ tetraquark currents, and find that there are only two independent ones. We use…

We extend the nonrelativistic QCD framework to explore the nature of the newly discovered di-$J/\psi$ resonances. Assuming them as either molecule-like states or tetraquarks, we calculated their hadroproduction cross sections at the LHC. We…

Meson states with exotic quantum numbers arise naturally in a covariant bound-state framework in QCD. We investigate the consequences of shifting quark masses such that the states are no longer restricted to certain C-parities, but only by…

In this work we study the $D^* \bar{D}^*$ current with QCD sum rules. We write the correlation function using the general current corresponding to the $D^* \bar{D}^*$ system and then use spin projectors to obtain the correlation function in…

We confirm our previous prediction of a $d^*$ state with $I(J^P)=0(3^+)$ [Phys. Rev. C 60, 045203 (1999)] and report for the first time based on a microscopic calculation that $d^*$ is a hexaquark dominated exotic state as it has about 2/3…

We construct the $\Sigma$-type currents to investigate the D-wave charmed baryon states with the QCD sum rules systematically. The predicted masses $M=3.35^{+0.13}_{-0.18}\,\rm{GeV}$ ($3.33^{+0.13}_{-0.16}\,\rm{GeV}$),…

In this paper, we construct eight pairs of hexaquark currents to search the $\Lambda_c\Sigma_c$ and $\bar{\Lambda}_c\Sigma_c$ dibaryon states via QCD sum rules. We show that the two currents of each pair are equivalent and we choose one of…

We investigate the resonance phenomenon in deeply bound charmoniumlike states. By interpreting the $Y(4220)$, $Y(4360)$, and $\psi(4415)$ states as deeply $S$-wave bound $D \bar D_1$, $D^* \bar D_1$, and $D^* \bar D_2^*$ molecules,…

We evaluate the masses and decay constants of the $0^+$ and $1^-$ open-charm $(\bar{c}\bar{d})(us)$ tetraquarks and molecular states from QCD spectral sum rules (QSSR) by using QCD Laplace sum rule (LSR). This method takes into account the…

In this short review we present and discuss all the experimental information about the charged exotic charmonium states, which have been observed over the last five years. We try to understand their properties such as masses and decay…

We have studied the mass spectra of doubly charmed pentaquark states in the $\Lambda _{c}^{(*)}D^{(*)}$ and $\Sigma _{c}^{(*)}D^{(*)}$ channels with $J^P=1/2^\pm$, $3/2^\pm$ and $5/2^\pm$ within the framework of QCD sum rules. We use the…

We have studied the $N D^* \bar{K}^*$ system in the framework of the Fixed Center Approximation to the Faddeev equations, taking the exotic $D^* \bar{K}^* $ system as the cluster and allowing the N to interact with the components of the…

We study the exotic $J^{PC}=0^{--}$ four-quark states in Laplace sum rules (LSR) and finite energy sum rules (FESR). We use the vector tetraquark-like currents as interpolating currents in the correlator, from which the $1^{+-}$ states are…

The decay $D^0 \to \pi^+ \pi^- \pi^0$ appears to be dominated by $\rho \pi$ states in a configuration of zero total isotopic spin. The spin $J$, parity $P$, and charge-conjugation eigenvalue $C$ of this final state are therefore $J^{PC} =…

We study the interaction of two $ D^* $ and a $\bar{K}^{*}$ by using the Fixed Center Approximation to the Faddeev equations to search for bound states of the three body system. Since the $ D^* D^* $ interaction is attractive and gives a…

We review recent studies on exotic states at the Belle experiment. The results include: (1) The measurement of the cross sections of $\gamma \gamma \to \omega \phi$, $\phi\phi$, and $\omega \omega$ for masses that range from threshold to…

We apply the method of QCD sum rules to study the structure $X$ newly observed by the BESIII Collaboration in the $\phi \eta^\prime$ mass spectrum in 2.0-2.1 GeV region in the $J/\psi \rightarrow \phi \eta \eta^\prime$ decay. We construct…