Related papers: The X(3872) boson: Molecule or charmonium
If the recently-discovered charmonium state X(3870) is a loosely-bound molecule of the charm mesons D^0 and \bar D^{*0} or \bar D^0 and D^{*0}, it can be produced in e^+ e^- annihilation at the \Upsilon(4S) resonance by the coalescence of…
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 very recent analysis by BaBar Collaboration indicates that the $X(3872)$ may favor the quantum number $J^{PC}=2^{-+}$ rather than the previously assumed $1^{++}$. By pretending the $\eta_{c2}(1D)$ charmonium to be the $X(3872)$, we…
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…
Three more $X$ particles are established in the 2014 Particle Data compared with the 2012 ones. There are now five established $X$ particles named as $X(3872)$, $X(3900)$, $X(4260)$, $X(4360)$, and $X(4660)$. Since the first $X$ particle…
The two excited vector charmonium states $Y(4220)$ and $Y(4360)$ are difficult to be understood as pure $c\bar{c}$ charmonium states. Since they are located close to the mass thresholds of $\bar{D}D_{1}$ and $\bar{D}^*D_{1}$, they can be…
In this Letter we interpret the Y(4260), a state recently discovered by the BaBar Collaboration that has a mass within the range of conventional charmonium states, as having a molecular-state structure. In our scheme this molecular-like…
We re-examine the re-scattering mechanism for the X(3872), as a candidate for the 2P charmonium state $\chi_{c1}(2P)$, decaying to $J/\psi\rho(\omega)$ through exchanging $D^{(*)}$ mesons between intermediate states $D(\bar{D})$ and…
I briefly review the properties of the hidden charm meson X(3872), discussing some puzzling aspects concerning its theoretical interpretation.
Using proton-proton collision data, corresponding to an integrated luminosity of 9$fb^{-1}$, collected with the~LHCb detector between 2011 and 2018, a new narrow charmonium state, the $X(3842)$ resonance, is observed in the decay modes…
The X(3872) and Y(4260), both discovered in $\pi^+\pi^- J/\psi$ mode, are rather unusual: $X_c\equiv X(3872)$ is very narrow, while $Y_c \equiv Y(4260)$ has large $Y_c\to \pi^+\pi^-J/\psi$ width. Many models for their composition have been…
We examine possible J^PC quantum number assignments for the X(3872). Angular correlations between final state particles in X(3872) --> pi+pi- J/psi decays are used to rule out J^PC values of 0++ and 0-+. The shape of the pi+pi- mass…
The LHCb collaboration has found that the production rate of $X(3872)$ in proton-proton collisions decreases as final state particle multiplicity increases. Moreover, the ALICE experiment at CERN has observed that the number of deuterons…
In 2003 the X(3872) particle was discovered by the Belle collaboration. Despite results collected since then, the nature of the state still remains unclear. In this contribution we report on new results on properties of the X(3872) state…
The internal structure of the near-threshold exotic hadrons, $T_{cc}$ and $X(3872)$, are studied by respecting the decay and coupled-channel contributions. The effective field theory model is introduced to calculate the compositeness, the…
The quantum numbers J^PC = 1++ of the X(3872) and the proximity of its mass to the D*0 anti-D0 threshold imply that it is either a loosely-bound hadronic molecule whose constituents are a superposition of D*0 anti-D0 and D0 anti-D*0 or it…
New data for X(3872) production in B decays provide a separation between X production and decay, sharpen several experimental puzzles and impose serious constraints on all models. Both charged and neutral B decays produce a narrow neutral…
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…
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…
The X(3872) with quantum numbers J(PC) = 1(++) is considered as a composite state containing both molecular hadronic and a c bar(c) component. Based on this structure assumption we first constrain model parameters in order to reproduce the…