Related papers: Aspects of Charmonium Physics
Using substantially larger data samples collected by the CLEO III detector, we report on new measurements of the decays of Upsilon(1S) to charmonium final states, including J/Psi, psi(2S), and chi_cJ. The latter two are first observations…
We present measurements of the charmonium state $h_c(^1P_1)$ made with 106M $\psi'$ events collected by BESIII at BEPCII. Clear signals are observed for $\psi'\to\pi^0 h_c$ with and without the subsequent radiative decay…
It is pointed out that the diagonal amplitude of the $E1-E1$ chromo-electric interaction with soft gluon fields (chromo-polarizability) can be measured directly for the $J/\psi$ and $\Upsilon$ resonances in the decays $J/\psi \to \pi \pi…
The early production of heavy quarks ($c\bar{c}$ and $b\bar{b}$) makes charmonia an ideal probe to study the evolution of the hot and dense medium produced in ultra-relativistic heavy-ion collisions, known as the quark--gluon plasma (QGP).…
Recent theoretical progress in calculations of the spectrum and decays of charmonium is reviewed. Traditionally, our understanding of charmonium was based on potential models. This is now being replaced by first principles.
We study the changes in the partial decay widths of excited charmonium states into $D \bar{D}$, when the D meson mass decreases in nuclear matter, taking the internal structure of the hadrons into account. Calculations within the 3P0 model…
The motion of charmonium in heavy ion collisions is described by a three dimensional transport equation with initial production and continuous regeneration in hot medium. The observation of apparently stronger $J/\psi$ suppression at…
A theoretical explanation of the observed splittings among the P~states of charmonium is given with the use of a nonsingular potential model for heavy quarkonia. We also show that the recently observed mass difference between the center of…
The mass components of charmoniumlike states are investigated through the decomposition of QCD energy-momentum tensor (EMT) on lattice. The quark mass contribution $\langle H_m\rangle$ and the momentum fraction $\langle x\rangle$ of valence…
This talk reviews recent experimental results on selected topics in the spectroscopy of charmonia, charmonium-like states and light mesons.
We analyze the theoretical description of radiative decays in charmonium. We use an elementary emission decay model to build the most general electromagnetic transition operator. We show that accurate results for the widths can be obtained…
We study the possible charmonium-like states with $J^{PC}=0^{--}, 0^{-+}$ using the tetraquark interpolating currents with the QCD sum rules approach. The extracted masses are around 4.5 GeV for the $0^{--}$ charmonium-like states and 4.6…
The extend to which geometrical effects contribute to the production and suppression of the $J/\psi$ and $q\bar{q}$ minijet pairs in general is investigated for high energy heavy ion collisions at SPS, RHIC and LHC energies. For the energy…
Using the two-component model that includes charmonium production from initial nucleon-nucleon hard scattering and regeneration in the produced quark-gluon plasma, we study $J/\psi$ production in heavy ion collisions at SPS, RHIC and LHC.…
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…
A new explanation for the longstanding puzzle of the tiny branching fraction of psi' --> rho pi relative to that for J/psi --> rho pi was proposed. In the case of J/psi, we argue that this decay is dominated by a higher Fock state in which…
The review on experimental results on charmonium and charmonium-like spectroscopy from B-factories is presented. Main theoretical interpretations, such as conventional charmonium, molecular state, hybrids, tetraquarks and others are…
Very recently, the Belle and BESIII experiments observed a new charmonium-like state $X(3823)$, which is a good candidate for the $D$-wave charmonium $\psi(1^3D_2)$. Because the $X(3823)$ is just near the $D\bar{D}^*$ threshold, the decay…
We investigate the two-photon transitions $H_{c\bar c} \to \gamma^*\gamma$ of the charmonium system in light-front dynamics. The light-front wave functions were obtained from solving the effective Hamiltonian based on light-front holography…
We study the charmonium spectrum using a complete one gluon exchange approach based on a phenomenological relativistic $q\bar{q}$ potential model with Dirac spinors in momentum space. We use phenomenological screening factors to include…