Related papers: The X(3872) at the Tevatron

The high-mass spectrum of lepton and photon pairs is sensitive to a broad range of new physics. Examples are extra dimensions and new gauge bosons such as the W' and Z'. Additionally, electron compositeness would result in excited electrons…

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…

If the quantum numbers of the X(3872) are J^{PC}=1^{++}, the measurement of its mass implies that it is either a loosely-bound hadronic molecule whose constituents are a superposition of the charm mesons pairs D^{*0} Dbar^0 and D^0…

More than twenty years have elapsed since the discovery of $\chi_{c1}(3872)$ (previously denoted as $X(3872)$), and an impressive amount of theoretical and experimental studies has been devoted to its properties, decays and production…

From a study of the X(3872) mass and width based on the world's largest sample of $X(3872)\to J/\psi\pi^+\pi^-$ decays, we find that our X(3872) signal is consistent with a single state, and leads to the most precise measurement of the…

The BABAR Collaboration performed a search for xi(2220) production in the initial-state radiation process e^+e^- --> gamma J/psi, J/psi --> gamma K^+K^- or J/psi --> gamma K^0_SK^0_S. No evidence for the xi(2220) resonance has been found.…

A new tetra-quark interpretation of X(3872) is presented. In this model, X(3872) consists of two degenerate tetra-quark mesons, {[cn](cbar nbar) +- (cn)[cbar nbar]}_{I=0}, and, therefore, it is naturally understood that X(3872) decays into…

Contrary to almost standard opinion that the X(3872) resonance is the D^{*0}\bar D^0+c.c. molecule or the qc\bar q\bar c four-quark state, we discuss the scenario where the X(3872)resonance is the c\bar c = \chi_{c1}(2P) charmonium which…

It is pointed out that in the decays $X(3872) \to D {\bar D} \gamma$ the possible `molecular' component of the X(3872) should give rise essentially only to a $D^0 {\bar D}^0 \gamma$ final state with a predictable spectrum, and should yield…

We study the decay B- --> J/psi K- pi+ pi- using 117 million BBbar events collected at the Y(4S) resonance with the BaBar detector at the PEP-II e+ e- asymmetric-energy storage ring. We measure the branching fractions Br(B- --> J/psi K- pi+…

We use QCD sum rules to calculate the width of the radiative decay of the meson X(3872), assumed to be a mixture between charmonium and exotic molecular $[c\bar{q}][q\bar{c}]$ states with $J^{PC}=1^{++}$. We find that in a small range for…

We discuss a possible interpretation of the open charm mesons $D_{s0}^*(2317)$, $D_{s1}(2460)$ and the hidden charm mesons X(3872), Y(3940) and Y(4140) as hadron molecules. Using a phenomenological Lagrangian approach we review the strong…

The calculation of the decay $X(3872)\to D^0 \bar{D}^0 \pi^0$ in effective field theory is revisited to include final state $\pi^0 D^0$, $\pi^0 \bar{D}^0$and $D^0\bar{D}^0$ rescattering diagrams. These introduce significant uncertainty into…

We present a search for the decay $X(3872) \to \pi^+\pi^-\pi^0$ in the $(772\pm11)\times10^6$ $\Upsilon(4S)\to B \bar B$ data sample collected at the Belle detector, where the $X(3872)$ is produced in $B^{\pm}\to K^{\pm}X(3872)$ and…

We study the $e^+e^-\to\gamma\omega J/\psi$ process using $11.6 ~\rm fb^{-1}$ $e^+ e^-$ annihilation data taken at center-of-mass energies from $\sqrt{s}=4.008~\rm GeV$ to $4.600~\rm GeV$ with the BESIII detector at the BEPCII storage ring.…

e+e- Experiments producing charmonium are reviewed. It is found that the contribution of the continuum amplitude via virtual photon was neglected in almost all the experiments and the channels analyzed. It is shown that the contribution of…

Spectroscopy results for Belle and BaBar are reported. A particular focus is put on new results of the X(3872) state with its radiative decays to $J$/$\psi$$\gamma$ and $\psi'$$\gamma$, its decay into $J$/$\psi$3$\pi$ and the search for…

Amplitude analysis is a powerful tool to study the properties of intermediate resonances produced in the decays of B mesons. At LHCb we have studied B+ decays to X(3872) K+, where X(3872) decays to J/psi pi+ pi-, to determine the quantum…

We study the decays $B_{c,u,d}\to X(3872)P$ in the perturbative QCD (PQCD) approach, where the puzzling resonance $X(3872)$ is involved and $P$ represents a light pseudoscalar meson $K$ and $\pi$. Assuming the $X(3872)$ as a $1^{++}$…

Resonant structures in the dipion mass spectrum from $\chi_{c1}(3872)\to\pi^+\pi^- J/\psi$ decays, produced via $B^+\to K^+\chi_{c1}(3872)$ decays, are analyzed using proton-proton collision data collected by the LHCb experiment,…