Related papers: Study of the $Z_c^+$ channel using lattice QCD
Several charged charmonium-like hadrons called $Z_c$ have been recently discovered by different experiments. In contrast to conventional hadrons these contain at least two valence quarks and antiquarks ($\bar{c}c\bar{d}u$). We perform a…
Recently three experiments reported a discovery of manifestly exotic Z_c^+(3900) in the decay to J/psi pi+, while J and P are experimentally unknown. We search for this state on the lattice by simulating the channel with J^PC=1^+- and I=1,…
Many mesons with properties incompatible with a $\bar cc$ structure have already been discovered, e.g. the $Z_c$ mesons with isospin 1. We investigate the spectrum of exotic charmonium-like mesons using lattice QCD. The focus is on $\bar cc…
The $Z_{c}(3900)^\pm/Z_c(3885)^\pm$ and $Z_{c}(4020)^\pm$ are two charmonium-like structures discovered in the $\pi J/\psi$ and $D^\ast\bar D^{(\ast)}+h.c.$ invariant mass spectra. Their nature is puzzling due to their charge, which forces…
Many exotic charmoniumlike mesons have already been discovered experimentally, of which the $Z_c$ mesons with $I=1$ are prominent examples. We investigate $J^{PC}=1^{+\pm}$ states with flavor $\bar cc\bar qq$ ($q=u,d$) in $I=1$ using…
We present a lattice QCD study of hidden-charm hexaquarks with quark content $usc\bar{d}\bar{s}\bar{c}$ based on four ensembles of gauge configurations generated by CLQCD Collaboration with pion mass in the range of 220-300MeV. Four…
The BESIII Collaboration has observed a candidate for a $c \bar c s \bar u$ tetraquark $Z_{cs}$ at $(3982.5^{+1.8}_{-2.6} \pm 2.1)$ MeV and width $(12.8^{+5.3}_{-4.4} \pm 3.0)$ MeV, while the LHCb Collaboration has observed a $Z_{cs}$…
Three charmonium-like states were studied using lattice QCD. The candidate for X(3872) was found slightly below DD* threshold in the channel with J^PC=1^++ and I=0, where cc as well as DD* and $J/\psi \omega$ interpolating operators were…
We investigate the possibility of $qq^\prime \bar b \bar b$ tetraquark bound states using $n_f=2+1$ lattice QCD ensembles with pion masses $\simeq 164$, $299$, and $415$ MeV. Motivated by observations from heavy baryon phenomenology, we…
Recent results on the hadron spectroscopy from lattice QCD are reviewed with emphasis on the meson sector and in particular on quarkonium-like $XYZ$ states. I report on the first rigorous treatment of the near-threshold states $X(3872)$ and…
We study spin 1/2 isoscalar and isovector candidates in both parity channels for the recently discovered \Theta^+(1540) pentaquark particle in quenched lattice QCD. Our analysis takes into account all possible uncertainties, such as…
Inspired by the newly reported $Z_{cs}(3985)^{-}$ by the BESIII Collaboration, we systematically investigate the strange hidden-charm tetraquark systems $cs\bar{c}\bar{u}$ with two structures: meson-meson and diquark-antidiquark. Two quark…
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…
Two pentaquarks $P_{c}^{+}$ were discovered by LHCb collaboration as peaks in the proton-$J/\psi$ invariant mass. We perform the lattice QCD study of the scattering between $J/\psi$ meson and nucleon in the channels with…
Recently a novel hadronic state of mass 6.9 GeV, that decays mainly to a pair of charmonia, was observed in LHCb. The data also reveals a broader structure centered around 6490 MeV and suggests another unconfirmed resonance centered at…
We present results of meson and baryon spectroscopy using the Chirally Improved Dirac operator on lattices of size 16**3 x 32 with two mass-degenerate light sea quarks. Three ensembles with pion masses of 322(5), 470(4) and 525(7) MeV and…
We propose that the $X(3915)$ observed in the $J/\psi\,\omega$ channel is the same state as the $\chi_{c2}(3930)$, and the $X(3960)$, observed in the $D_s^+D_s^-$ channel, is an $S$-wave $D_s^+ D_s^-$ hadronic molecule. In addition, the…
We have studied the loosely bound $D^*\bar{D}^*$ system. Our results indicate that the recently observed charged charmonium-like structure $Z_c(4025)$ can be an ideal $D^*\bar{D}^*$ molecular state. We have also investigated its pionic,…
Results of hadron spectroscopy with two dynamical mass-degenerate chirally improved quarks are presented. Three ensembles with pion masses of 322(5), 470(4) and 525(7) MeV, lattices of size 16^3 \times 32, and lattice spacings close to 0.15…
We develop a moment QCD sum rule method augmented by fundamental inequalities to study the existence of exotic doubly hidden-charm/bottom tetraquark states made of four heavy quarks. Using the compact diquark-antidiquark configuration, we…