Related papers: Single eta production in heavy quarkonia: breakdow…
Quarkonia are some of the most important probes of the medium created in relativistic heavy ion collision experiments, but it is still difficult to get quantitative results for its behavior in the plasma. Here I discuss the decay width of a…
Differential cross sections for eta photoproduction off protons have been measured at E_gamma = 1.6 - 2.4 GeV in the backward direction. A bump structure has been observed above 2.0 GeV in the total energy. No such bump is observed in cross…
In these proceedings we present our results on the exclusive photoproduction of $J/\psi\,\eta_{c}$ pairs in the collinear factorization framework. We argue that the process might be used as a complementary channel for studying the…
We present here a comprehensive model to describe the bottomonium suppression data obtained from the CERN Large Hadron Collider (LHC) at center-of-mass energy of $\sqrt{s_{NN}}=2.76$ TeV. We employ a quasiparticle model (QPM) equation of…
We study magnetic dipole (M1) transitions between two quarkonia in the framework of non-relativistic effective field theories of QCD. Relativistic corrections of relative order v^2 are investigated in a systematic fashion. Non-perturbative…
We describe production of heavy quarkonia in pA collisions within the dipole approach, assuming dominance of the perturbative color-singlet mechanism (CSM) in the $p_T$-integrated cross section. Although accounting for a nonzero heavy…
We report a first theoretical study for neutrino-induced diffractive productions of heavy pseudoscalar mesons, \eta_c and \eta_b, off a nucleon. Based on factorization formalism for exclusive processes, we evaluate the forward diffractive…
This thesis can be divided into several parts. The first one consists in a detailed historical review of quarkonium physics, centered on the different production models successively introduced. Then comes a review of the currently available…
We study the production of bottomonium states in heavy-ion reactions at collider energies available at RHIC and LHC. We employ an earlier constructed rate equation approach which accounts for both suppression and regeneration mechanisms in…
In this talk I review the recent progress made in the calculations of quarkonia production in fixed target experiments. NRQCD organizes the calculations in a systematic expansion in $\alpha_s$ and $v$, the relative velocity between the…
Recent progress on the bottomonium states is reported. This talk briefly reviews the observation of $h_b(1P), h_b(2P), Z_{b1}^+, Z_{b2}^+$ states, transition of $h_b(nP)\to \eta_b(mS)\gamma$ and new studies on the $\eta_b(2S)$ state. Other…
In this work we study the radiative decay widths of vector quarkonia for the process of $J/\psi(nS)\rightarrow\eta_{c}(nS)\gamma$ and $\Upsilon(nS)\rightarrow\eta_{b}(nS)\gamma$ (for principal quantum numbers $n=1, 2, 3$) in the framework…
In this article, we perform an systematic study of the radiative transitions among the bottomonium states based on the heavy quarkonium effective theory, and make predictions for the ratios among the radiative decay widths of a special…
Motivated by the success of Modified Non-Relativistic Quantum Chromodynamics (Modified NRQCD) in explaining data from experiments at the Large Hadron Collider (LHC) for charmonia, we now turn to the study of bottomonium production at the…
Within the nonrelativistic quantum chromodynamics framework, we make a comprehensive study on the exclusive production of excited charmonium and bottomonium in $e^+e^-\to \gamma^*/Z^0 \to|(Q\bar{Q})[n]\rangle +\gamma$ ($Q=c$ or $b$ quarks)…
The conventional wisdom in dealing with electromagnetic transition between heavy quarkonia is the multipole expansion, when the emitted photon has a typical energy of order quarkonium binding energy. Nevertheless, in the case when the…
Some new results on magnetic dipole (M1) transitions in heavy quarkonium from nonrelativistic effective field theories of QCD are briefly reported. This model-independent approach not only facilitates a systematic and lucid way to…
The possibility to observe new bottomonium states with $J^{PC}= 1^{--}$ in the region $10.7-11.1$ GeV is discussed. The analysis of the di-electron widths shows that the $(n+1)^3S_1$ and $n^3D_1$ states ($n\geq 3$) may be mixed with a…
The ratio of the photon mediated production or annihilation rates of spin triplet and spin singlet heavy quarkonium states is computed to the next-to-next-to-leading logarithmic accuracy within the nonrelativistic renormalization group…
Using a temperature-dependent potential obtained from lattice gauge calculations, we study the stability of heavy quarkonia in the quark-gluon plasma. We find that only the Upsilon(1S) and the eta_b(1S) are bound in the quark-gluon plasma,…