Related papers: Charmonium pair production in ultraperipheral coll…
Ultra-peripheral collisions (UPCs), studied using the ALICE detector, allow us to investigate the low-$x$ behavior of the gluon distribution of the colliding particles. Two new measurements of coherent J/$\psi$ photoproduction cross section…
In the limit of heavy quark mass, the production cross section and polarization of quarkonia can be calculated in perturbative QCD. We study the $p_\perp$-averaged production of charmonium states in $\pi N$ collisions at fixed target…
Charmonium production in high-energy collisions can be split into a prompt and a non-prompt component. Both components can be distinguished experimentally by studying displaced topology, and represent valuable tools to investigate the…
The coherent photoproduction of $\rm{J/\psi}$ and $\rm{\psi'}$ mesons was measured in ultra-peripheral Pb-Pb collisions at a center-of-mass energy $\sqrt{s_{\mathrm{NN}}}~=~5.02$ TeV with the ALICE detector. Charmonia are detected in the…
As predicted by theory and confirmed by measurements, one, two or three neutrons are emitted frequently in ultraperipheral collisions (UPCs) of heavy relativistic nuclei, in particular, $^{208}$Pb. The exchange of low-energy…
Charmonium production at heavy-ion colliders is considered within the comovers interaction model. The formalism is extended by including possible secondary J/psi production through recombination and an estimate of recombination effects is…
We study the inelastic charmonium ($J/\psi$, $\psi(2S)$) and bottomonium ($\Upsilon(nS)$) photoproduction and fragmentation processes in $p$-$p$ and $Pb$-$Pb$ collisions at LHC energies, where the ultra-incoherent photon emission is…
Heavy quarkonium production is an excellent tool to test both perturbative and non-perturbative QCD, as perturbative QCD can describe the heavy quark production process, while the formation of the quarkonium bound state involves…
In this paper, we study double charmonia production in Upsilon peaks, especially, a S-wave charmonium $\eta_c$ and a P-wave charmonium $h_c(^1P_1)$, or a S-wave charmonium $J/\psi$ and the $X(3940)$ and $X(4160)$ within the nonrelativistic…
In this paper, we report on the calculation of the cross section of J/\Psi plus jet inclusive production in direct two-photon collisions at next-to-leading order within the factorization formalism of nonrelativistic quantum chromodynamics…
We provide an update on our semi-classical transport approach for quarkonium production in high-energy heavy-ion collisions, focusing on $J/\psi$ and $\psi(2S)$ mesons in 5.02 TeV Pb-Pb collisions at the Large Hadron Collider (LHC) at both…
Inclusive production of $\Upsilon J/\psi$ pair in proton-proton interation at LHCb is considered. This process is forbidden at leading order of perturbation theory, so such channels as double parton scattering, $\chi_b\chi_c$ pair…
Charmonium production is a probe sensitive to deconfinement in nucleus--nucleus collisions. The production of J/$\psi$ via regeneration within the QGP or at the phase boundary has been identified as an important ingredient for the…
We present a new analysis of double charmonium production in e^+ e^- annihilation. The observation of the processes e^+ e^- -> J/psi eta_c, J/psi chi_c0, and J/psi eta_c(2S) is confirmed using a dataset more than three times larger than…
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…
We discuss the physics of large impact parameter interactions at the LHC: ultraperipheral collisions (UPCs). The dominant processes in UPCs are photon-nucleon (nucleus) interactions. The current LHC detector configurations can explore small…
The ALICE Collaboration reports three measurements in ultra-peripheral proton$-$lead collisions at forward rapidity. The exclusive two-photon process \ggmm and the exclusive photoproduction of J/$\psi$ are studied. J/$\psi$ photoproduction…
We present predictions for the rapidity-differential cross sections of exclusive $\Upsilon$ photoproduction in ultraperipheral collisions (UPCs) of lead ions at the Large Hadron Collider (LHC). We work in the framework of collinear…
We calculate the cross section of J/psi plus prompt-photon inclusive production in gamma gamma collisions at next-to-leading order within the factorization formalism of nonrelativistic quantum chromodynamics (NRQCD) focusing on direct…
The CDF preliminary analysis on polarized charmonium production at moderate transverse momentum, $p_T \sim 4 - 20$ GeV, severely challenges the color octet model (COM), which predicts quarkonium to be transversely polarized with increasing…