相关论文: Quark structure of the $X(3872)$ and $\chi_b(3P)$ …
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…
In this paper, we calculate mass and probability fractions of meson-meson components of $X(3872)$ in an unquenched quark model. Different from most of other unquenched quark models, the quark pairs creation operator from $^3P_0$ is modified…
In this contribution, we will discuss our unquenched quark model re- sults for the spectra of cc and bb states. The spectra are calculated in the unquenched quark model formalism, where the physical mass of a meson is the sum of a bare mass…
In this contribution, we discuss our recent unquenched quark model results for the spectrum of $b \bar b$ mesons with self energy corrections, due to the coupling to the meson-meson continuum. Our unquenched quark model predictions for the…
We use QCD spectral sum rules to test the nature of the meson X(3872), assumed to be an exotic four-quark (c\bar{c}q\bar{q}) state with J^{PC}=1^{++}. For definiteness, we work with the current proposed recently by Maiani et al [1], at…
We calculate the masses of $\chi_{\rm c}(3P)$ states with threshold corrections in a coupled-channel model. The model was recently applied to the description of the properties of $\chi_{\rm c}(2P)$ and $\chi_{\rm b}(3P)$ multiplets [Phys.\…
We calculate the masses of $\chi_{\rm c}(2P)$ and $\chi_{\rm b}(3P)$ states with threshold corrections in a coupled-channel model. Here, the meson quarkonium core is augmented by higher Fock components due to pair-creation effects.…
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…
The structure of exotic resonances that do not trivially fit the usual quark model expectations has been a matter of intense scientific debate during the last two decades. A possible way of estimating the size of these states is to study…
Since the discovery of the $J/\psi$, the quark model was very successful in describing the spectrum and properties of heavy mesons including only $q\bar q$ components. However since 2003, with the discovery of the $X(3872)$, many states…
We generalise the framework of Dyson-Schwinger and Bethe-Salpeter equations for four-quark states to accommodate the case of unequal quark masses. As a first application, we consider the quantum numbers $I(J^{PC})=0(1^{++})$ of the…
Currently, the structure of the $X(3872)$ meson is unknown. Different competing models of the $c\bar c$ exotic state $X(3872)$ exist, including the possibilities that this state is either a mesonic molecule with dominating $D^0 \bar D^{*0}…
The properties of the resonance X(3872) are discussed under the assumption that this resonance is dominantly a `molecular' $J^{PC}=1^{++}$ state of neutral $D$ and $D^*$ mesons. It is argued that in these properties should dominate the…
A solvable coordinate-space model is employed to study the $c\bar{c}$ component of the X(3872) wave function, by coupling a confined $^3P_1$ $c\bar{c}$ state to the almost unbound $S$-wave $D^0\bar{D}^{*0}$ channel via the $^3P_0$…
The quantum numbers of the X(3872) meson are determined to be JPC = 1++ based on angular correlations in B+ to X(3872) K+ decays, where X(3872) to pi+pi- J/psi and J/psi to \mu+\mu-. The data correspond to 1.0 fb-1 of pp collisions…
Since the discovery of the $X(3872)$ the study of heavy meson molecules has been the subject of many investigations. On the experimental side different experiments have looked for its spin partners and the bottom analogs. On the theoretical…
Using the QCD spectral sum rule approach we investigate different currents with $J^{PC}=1^{++}$, which could be associated with the $X(3872)$ meson. Our results indicate that, with a four-quark or molecular structure, it is very difficult…
We explore the quark-mass dependence of the pole position of the X(3872) state within the molecular picture. The calculations are performed within the framework of a nonrelativistic Faddeev-type three-body equation for the $D\bar{D}\pi$…
A recent quark-model description of X(3872) as an unquenched $2\,{}^{3\!}P_1$ $c\bar{c}$ state is generalised by now including all relevant meson-meson configurations, in order to calculate the widths of the experimentally observed…
We study some of the main properties (masses and open-flavor strong decay widths) of $4P$ and $5P$ charmonia. While there are two candidates for the $\chi_{\rm c0}(4P,5P)$ states, the $X(4500)$ and $X(4700)$, the properties of the other…