Related papers: Extra charmonium states as bag-quarkonia
We study the anomalously large rates of some hadronic transitions observed in heavy quarkonia using a constituent quark model which has been successful in describing meson and baryon phenomenology. QCD multipole expansion (QCDME) is used to…
Exotic multi-quark states are examined in the quark model and in QCD. Current status of theoretical studies of the pentaquark Theta^+ is reported. We show recent analyses of multi-quark components of baryons. A novel method to extract a…
The lattice QCD simulations of charmonia and exotic charmonium-like states are reviewed. I report on the first exploratory simulation of charmonium resonances above open charm threshold which takes into account the strong decay. The puzzles…
Hadrons with explicit gluonic degrees of freedom, such as charmonium hybrids, are key to understanding nonperturbative behavior of strong interaction, yet they remain experimentally elusive. Within a constituent gluon model treating the…
I discuss issues related to charmonium production, in view of physics possibilities at a 15 ... 30 GeV continuous beam electron facility. High energy photo- and hadroproduction of heavy quarkonia presents several challenges to QCD models…
The charmonium system provides an opportunity to explore a wide variety of topics in hadronic physics. Studies of the properties of and transitions among cc-bar states yield insight into relativistic and non-perturbative QCD effects. At the…
We study charmonium and bottomonium as relativistic bound states in a light-front quantized Hamiltonian formalism. The effective Hamiltonian is based on light-front holography. We use a recently proposed longitudinal confinement to complete…
In this study, we analyze the bound-state energy spectrum of quark-antiquark systems using the semiclassical WKB approximation. We consider the Cornell potential, which combines a linear confinement term with a Coulombic interaction, and…
We present recent results in semileptonic and non-leptonic exclusive $B_c$ decays to charmonium states both in $S$-wave, $J/\psi$ and $\eta_c$, and in $P$-wave, $\chi_{cJ}$ and $h_c$. The analysis, based on the heavy quark spin symmetry…
Masses of the ground, orbitally and radially excited states of the asymmetric fully heavy tetraquarks, composed of charm (c) and bottom (b) quarks and antiquarks are calculated in the relativistic diquark-antidiquark picture. The…
Exotic hadrons of a few GeV/c^2 mass, exhibiting a spectrum determined by the perturbative interaction of a non-minimal number of valence quarks, have long been predicted as signals of the underlying QCD structure. Models that include the…
In recent years many vector charmonium(-like) states were reported by different electron-positron collider experiments above $4.2$ GeV. However, so far, there not only exists sizable tension in the parameters of those states, but there is…
Selected topics of exotics in leptonic machines are presented, including recent discovery of abnormal structures around the ppbar threshold and new information of the XYZ (charmonium-like) states.
We compute, for the first time using lattice QCD methods, radiative transition rates involving excited charmonium states, states of high spin and exotics. Utilizing a large basis of interpolating fields we are able to project out various…
We present a new method to study the properties of heavy quarks at finite temperature. It combines non-relativistic QCD with an improved gluonic action on anisotropic lattices. The efficiency of the approach is demonstrated by the first…
Charmonium spectral functions in vector and pseudoscalar channels at finite temperature are investigated through the complex Borel sum rules and the maximum entropy method. Our approach enables us to extract the peaks corresponding to the…
The exclusive processes are considered, where a point-like source of heavy quark-antiquark pairs $Q \bar Q$, e.g. their electromagnetic current, produces a pair consisting of a heavy quarkoniumlike exotic meson (tetraquark) or baryon…
We have studied the dominant radiative transitions of the charmonium $S$-and $P$-wave states within the covariant confined quark model. The gauge invariant leading-order transition amplitudes have been expressed by using either the…
Exotic hadron states beyond the conventional $qqq$ baryon and $q\bar{q}$ meson configurations are well expected from QCD. Having been successful in the past decades, the heavy quarkonium sector is proved to be an ideal place for the study…
New enhancements in the charmonium and bottomonium spectra observed since 2003 are very briefly reviewed. Special attention is paid to $\chi_{c1}(3872)$ (formerly $X(3872)$) owing to its remarkable proximity to the $\bar{D}^{\star0}\!D^0$…