Related papers: Charmoniumlike States at BESIII
We report the first observation of a new charmonium state at a mass of $(3.943 \pm 0.006 \pm 0.006) {GeV}/c^2$. This state, called X(3940), is observed in the process $e^+ e^- \to J/\psi X(3940)$ in the spectrum of masses recoiling against…
The observation of $Z_{cs}(3985)$ by BESIII in the $D_s^{*-}D^0$ and $D_s^{-}D^{*0}$ channel adds important dynamic information for a coherent understanding of both $Z_c(3900)$ and $Z_c(4020)$, as well as their strange partners…
I review here the most recent results about the observation and the study of hadronic bound states that do not fit well in the standard quarkonium picture. Several new states have been observed in the last few years, at B-, tau-Factories…
We search, for the first time, for an exotic molecular state with quantum numbers $J^{PC}=1^{-+}$, called $X$, via the process $e^{+}e^{-} \to \gamma D^{+}_{s} D_{s1}^{-}(2536) +c.c.$ using data samples corresponding to a luminosity of…
BESIII is a new state-of-the-art 4pi detector at the recently upgraded BEPCII two-ring e+e- collider at the Institute of High Energy Physics in Beijing. It has been in operation for three years, during which time it has collected the…
The observation of the exotic quarkonium state Z_c(3900) by the BESIII and Belle collaborations supports the concept of hadronic molecules. Charmonium states interpreted as such molecules would be bound states of heavy particles with small…
Many newly discovered mesons behave like $\ccbar$ charmonium states in that they preferentially decay into final states that contain a $c$- and a $\bar{c}$-quark, but do not fit expectations for any of the unfilled levels of the…
The Belle II experiment at the SuperKEKB asymmetric $e^+e^-$ collider at KEK, Tsukuba, Japan, is recording data since 2018. The expected high luminosity of $\mathcal{L}=8\cdot 10^{35}~$cm$^{-2}$s$^{-1}$ enables searches for yet unobserved…
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…
In this talk, we review the recent experimental developments on charmonium and charm spectroscopy base on the data samples taken by the BESIII, Belle, LHCb and CMS experiments. We concentrate on the resonant parameter measurement of…
We discuss methods and approaches to the description of molecular states in the spectrum of heavy quarks and investigate in detail various properties of the exotic charmonium-like state X(3872) in the framework of the mesonic molecule…
The original charmonium two-body problem, like the $c\bar c$ structure of the $J/\psi$ meson, has become more involved in the last few years with the discovery of new resonances such as the tentative molecular state $X(3872)$ or the…
Using effective Lagrangians constrained by the heavy quark spin symmetry and chiral symmetry, for the light quarks, we analyze the $D^0 D^0\pi^+$, $\bar{D}^0D^0\pi^0$ and $D^0\bar{D}^{*0}$ invariant mass spectra. Performing a simultaneous…
We calculate the E1 transition widths of higher vector charmonium states into the spin-triplet 2P states in three typical potential models, and discuss the possibility to detect these 2P states via these E1 transitions. We attempt to…
In these proceedings we summarise the recent studies of exotic hadrons performed at the LHC and Tevatron. The X(3872) production cross section and mass measurements are reported, along with the determination of its quantum numbers, the…
A number of charmonium- and bottomonium-like meson states have been observed that have properties that do not match well to expectations for the simple quark-antiquark substructure suggested by the constituent quark model. Some of them are…
At present very large data samples in the energy region of 2.0-4.6 GeV were accumulated by the BESIII detector, which is operated in the upgraded Beijing electron positron collider (BEPCII). These data samples provide an unprecedented…
I give a brief account of current topics in description of exotic multiquark mesonic resonances with hidden heavy ($c$ or $b$) flavor, the so-called XYZ states, in terms of hadronic molecules and hadro-quarkonium systems. Also discussed are…
From December 2019 to June 2021, the BESIII experiment collected about 5.85 fb$^{-1}$ of data at center-of-mass energies between 4.61 GeV and 4.95 GeV. This is the highest collision energy BEPCII has reached so far. The accumulated $e^+e^-$…
We have performed a combined analysis of the BESIII data for both the $Z_c(3900)$ and $Z_{cs}(3985)$ structures, assuming that the latter is an SU(3) flavor partner of the former one. We have improved on the previous analysis of Albaladejo…