Related papers: Short Range Structure in the X(3872)
Last year's X(3872) discovery was confirmed with the CDF II detector in pbarp collisions. We measure its mass to be $3871.3 \pm 0.7 \pm 0.4 MeV/c2$. The source of X-mesons in the large CDF sample is resolved by studying their vertex…
The recent observation of a hadronic resonance $d^*$ in the proton-neutron system with isospin $I = 0$ and spin-parity $J^P = 3^+$ raises the possibility of producing other novel six-quark dibaryon configurations allowed by QCD. A dramatic…
We report on a search for the recently reported X(3872) state using 15.1 fb^{-1} e+ e- data taken in the \sqrt{s} = 9.46-11.30 GeV region. Separate searches for the production of X(3872) in untagged gamma-gamma fusion and e+ e- annihilation…
Inspired by the BESIII newest observation of an axial-vector particle $X(2300)$ in the $\psi(3686)\rightarrow \phi\eta \eta'$ process, we simulate its production in $e^+e^-$ collisions at $\sqrt{s}=4.95$ GeV using the parton and hadron…
Inspired by the recent Altas and CMS experiments on the invariant mass spectrum of $J/\psi J/\psi$, we systematically study the $c\bar{c}c\bar{c}$ system of $J^{P}=0^{+}$. In the framework of chiral quark model, we have carried out…
The dipionic transition of the $X(3872)$ to the $\eta_c$ was investigated using an effective Lagrangian approach. In this study, the $X(3872)$ was assumed to be a $D\bar{D}^\ast + \text{c.c.}$ bound state with the quantum numbers…
In this letter, we propose interpolating currents for the X(3872) resonance, and show that, in the Heavy Quark limit of QCD, the X(3872) state should have degenerate partners, independent of its internal structure. Magnitudes of possible…
From a study of the lineshape of the $X(3872)$, the LHCb collaboration measures a sizeable negative effective range. This cannot be reconciled with a shallow $D\bar{D}^*$ bound state hypothesis. Based on Weinberg's compositeness criterion,…
We review the most recent experimental progress in the hadron spectroscopy, up to bottomonium mass. This covers the search for the J^PC=1^-+ exotic state, the states in J/psi decays, the spin-singlets of heavy quarkonium, and the…
We report recent results on the properties of the X(3872) produced via the B+ --> K+ X(3872) decay process. We observe X -->pi+pi-pi0 J/psi decays where the 3pi invariant masses cluster near the upper kinematic boundary suggesting that they…
We present preliminary simulation results for the I = 0 charmonium state $X(3872)(1^{++})$ and the I = 1 charmonium state $Z_c^+(3900)(1^{+-})$. The study is performed on gauge field configurations with 2+1+1 flavors of highly improved…
Recent results by BELLE and BaBar point to the existence of a second X particle decaying in D^0 D^0bar pi^0, a few MeV above the X(3872). We identify the two X states with the neutral particles predicted by the 4-quark model and show that…
We have searched for exclusive production of exotic charmonia in the reaction $\mu^+~N \rightarrow \mu^+ (J\!/\!\psi\pi^+\pi^-)\pi^{\pm}~N'$ using COMPASS data collected with incoming muons of 160 GeV/$c$ and 200 GeV/$c$ momentum. In the…
The 2020 announcement by LHCb of a narrow structure $X(6900)$ in the di-$J/\psi$ spectrum -- a potential $c\bar c c\bar c$ state -- has opened a new era in hadronic spectroscopy. In this talk, we briefly survey theory works preceding this…
The $X(3872)$ is the first and the most interesting one amongst the abundant $XYZ$ states. Its mass coincides exactly with the $D^0\bar D^{*0}$ threshold with an uncertainty of 180 keV. Precise knowledge of its mass is crucial to understand…
We present results on the X(3872), produced in $B^+ \to X(3872) K^+$ and $B^0 \to X(3872) K^0_S$ decays where $X(3872) \to J/\psi \pi^+ \pi^-$. We report the first statistically significant observation of $B^0 \to X(3872) K^0_S$ and measure…
The X(3872) is one of the most puzzling resonances ever observed. First seen by the Belle Collaboration in 2003, it solicited the effort of a hundred of experimental physicists and dozens of theorists, who nowadays are trying yet to shed…
We present an estimate of the partial width of X(3872) into p p-bar under the assumption that it is a weakly-bound hadronic molecule whose constituents are a superposition of the charm mesons D^{*0} D-bar^0 and D^{0} D-bar^{*0}. The p p-bar…
The strong and electromagnetic decays of $X(4350)$ with quantum numbers $J^P =0^{++}$ and $2^{++}$ have been studied by using the effective Lagrangian approach. The coupling constant between $X(4350)$ and $D_s^{\ast}D_{s0}^{\ast}$ is…
The processes $X(3872)\to D^{*0}\bar{D^{0}}+c.c.,~\gamma J/\psi,~\gamma \psi(2S),$ and $\gamma D^{+}D^{-}$ are searched for in a $9.0~\rm fb^{-1}$ data sample collected at center-of-mass energies between $4.178$ and $4.278$ GeV with the…