Related papers: XYZ States - Results from Experiments
We present a concise review of the vector charmonium state $\psi(4230)$, which was originally labelled as $Y(4260)$ in the literature. As one of the earliest candidates for a QCD exotic states, its interpretation has initiated various ideas…
The recent results on Charmonium and Charmonium-like states at BESIII are reviewed, including the observation of $\rm Z_{cs}(3985)$ state, the study of the new decay modes of $\psi_2(3823)$ state, observation of resonance structure in $\rm…
We review recent charmonium and charmonium-like state from the BaBar B-factory. A particular focus is given to the observation of the decay $X(3872) \to J/\psi \omega$ and to recent $\eta_{c}(1S)$ and $\eta_{c}(2S)$ results. The Observation…
We discuss decays and productions for the possible molecular states formed by bottom mesons B (B*) and anti-B (anti-B*). The twin resonances found by Belle, Zb(10610) and Zb(10650), are such candidates. The spin wave functions of the…
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 consider $X(3872)$ and $Y(4140)$ as the vector tetraquark states of $X_c^0\equiv c\bar c u\bar u(d\bar d)$ and $c\bar c s\bar s$, respectively. By connecting $\Lambda_b\to X_c^0\Lambda$ to $B^-\to X_c^0 K^-$, we predict that the…
The positive parity $\chi_{cJ}(2P)$ charmonium states are expected to lie around the 3.9 GeV/$c^2$ energy region, according to the predictions of quark models. However, a plethora of states with difficult assignment and unconventional…
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…
The spectrum of hadrons is important for understanding the confinement of quantum chromodynamics. Many new puzzles arose since 2003 due to the abundance of experimental discoveries with the $XYZ$ structures in the heavy quarkonium mass…
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…
Exotic charmonium and bottonomium resonances recently discovered are discussed and interpreted as diquark-antidiquark states containing a pair of charm quarks and a pair of light, up and down, quarks. Successes, shortcomings and predictions…
Four exotic charmonium-like states, i.e. $X(4140)$, $X(4274)$, $X(4500)$, and $X(4700)$, have been observed very recently by LHCb Collaboration in the decay process $B^+\to J/\psi \phi K^+$ using the 3${\rm fb}^{-1}$ data of $p\bar p$…
Exotic states have been predicted before and after the advent of QCD. In the last decades they have been observed at accelerator experiments in the sector with two heavy quarks, at or above the quarkonium strong decay threshold and called X…
Exotic states in the charmonium family are systematically treated in the framework of simplest model with an effective coulomb-like interaction of heavy quark and antiquark in the presence of static excitation of quark-gluon modes…
We present a quark model calculation of the charmonium spectrum with self energy corrections due to the coupling to the meson-meson continuum. The bare masses used in the calculation are computed within the relativized quark model by…
The X(3872) and Y(4260), among a host of charmonium-like mesons, have rather unusual properties: the former has very small total width, the latter has large rate into $\pi^+\pi^-J/\psi$ channel. It would not be easy to settle between the…
A study of various bottomonium states, in Y(2S)-> gamma (b b-bar) decays, reconstructed exclusively in 26 hadronic final states is presented. The study is performed using a data sample recorded at the Y(2S) resonance with the Belle detector…
The bottomonium spectrum is systematically studied within an unquenched quark model. Based on a good description of both the masses and widths for the well-established states, we further give predictions for the higher $S$-, $P$-, and…
In this work, we adopt the one-boson exchange model to analyze the $D^{(*)}_{(s)}B^{(*)}_{(s)}$ interactions from a coupled-channel perspective. For the $I(J^{P})=1(1^{+})$ $DB^{*}/D^*B/D^*B^{*}$ system, employing the complex scaling…
I. Light Scalars as Four-quark States II. Isotensor Tensor Tensor E(1500-1600) State III. X(3872) State as Charmonium \chi_{c1}(2P) IV. Two-gluon Annihilation of Charmonium \chi_{c2}(2P) There are considered problems of the exotic states,…