相关论文: Pionic transitions from X(3872) to chi_{cJ}
Two-pion transitions in charmonium and bottomonium are considered with the leading relativistic effects taken into account. The contribution of the chromo- magnetic interaction of the charmed quarks to the amplitude of the decay $\psi(2S)…
The recent observation and measurement of the decay $Z_c(3900) \to \rho \eta_c$ provides the data on the relative strength of the pion and $\rho$ coupling in the corresponding transitions between exotic resonances and pure heavy quarkonium.…
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 report recent results on the properties of the X(3872) produced via the B-->KX(3872) decay process in the Belle detector. We compare these properties with expectations for possible charmonium-state assignments.
Meson states with exotic quantum numbers arise naturally in a covariant bound-state framework in QCD. We investigate the consequences of shifting quark masses such that the states are no longer restricted to certain C-parities, but only by…
The medium modifications of the masses of the charmonium states (J/$\psi$, $\psi$(3686) and $\psi$(3770)) in asymmetric nuclear matter in the presence of strong magnetic fields are studied using an effective chiral model. The mass…
We deploy a kinetic-rate equation to evaluate the transport of $J/\psi$, $\psi(2S)$, $B_c$ and X(3872) in ultra-relativistic heavy-ion collisions and compare their production yields to experimental data from the Large Hadron Collider. The…
The chromomagnetic interaction, with proper account for flavour-symmetry breaking, is shown to explain the mass and coupling properties of the X(3872) resonance as a $J^{PC}$ = 1$^{++}$ state consisting of a heavy quark-antiquark pair and a…
The anomalously large rates of some hadronic transitions from quarkonium are studied using QCD multipole expansion (QCDME) in the framework of a constituent quark model which has been successful in describing hadronic phenomenology. The…
In this talk, I review the recent experimental developments on charmonium. These mainly include the precision measurements of spin-singlet states $\etac$, $\etac(2S)$, $h_c$, studies of the charmonium-like states X(3872) and the $Y$ states.…
The effects of virtual light quark pairs on the charmonium spectrum are studied. Pair creation is modelled with a ``$^{3}P_{0}$" vertex and intermediate states are summed up to 2S excitations. Quark model parameters are obtained by fitting…
We study radiative decays of heavy $Q{\bar Q}$ states, both for $Q=c$ and $Q=b$, using an effective Lagrangian approach which exploits spin symmetry for such states. We use existing data on radiative quarkonium transitions to predict some…
Pion exchange in S-wave between hadrons that are themselves in a relative S-wave is shown to shift energies by hundreds of MeV, leading to deeply bound quasi-molecular states. In the case of charmed mesons $D^*,D_1$ a spectroscopy arises…
In this article, we study the radiative decays among the charmonium states with the heavy quark effective theory, and make predictions for the ratios among the radiative decay widths of an special multiplet to another multiplet. The…
In QCD with two massless quarks, the chiral phase transition is plausibly in the same universality class as the classical O(4) magnet. To test this hypothesis, critical exponents characterizing the behaviour of universal quantities near the…
It has been argued that the mystery boson X(3872) is a molecule state consisting of primarily D0-D0*bar + D0bar-D*0. In contrast, apparent puzzles and potential difficulties have been pointed out for the charmonium assignment of X(3872). We…
We show that the literature on pion exchange between charm and bottom mesons is inconsistent. We derive the formalism explicitly, expose differences between papers in the literature and clarify the implications. We show that the X(3872) can…
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…
Hadronic transitions of the chi(cj)(1P) states have not been studied yet. We calculate the rate of the hadronic transition chi(c1)(1P) to eta(c) plus two pions in the framework of QCD multipole expansion. We show that this process can be…
In this talk, we review the most recent progress in the searching for the exotic hadrons, including hybrids, multi-quark states, molecules and so on. We only focus on the studies with a charmonium and one or more light mesons in the final…