Related papers: Quarkonium Production through Hard Comover Scatter…
Quarkonium production is a sensitive probe of the dynamics of hard scattering, which can `measure' the environment of the heavy quark pair after it is created in a hard process. Quarkonium hadroproduction data indicates that the produced…
We extend to large transverse momentum pt an approach to quarkonium hadroproduction previously suggested for low pt. The dynamics involves a perturbative rescattering of the heavy quark pair off a comoving color field which originates from…
The cross sections of heavy quark production in $pp$ collision and for their photo- and electroproduction are calculated in the framework of QCD. The virtual nature of the interacting gluons as well as their transverse motion and different…
We calculate the heavy quarkonium production in double pomeron exchange processes in perturbative QCD by using two-gluon exchange model. For the $P$-wave $\chi_J$ productions, we find $\chi_1$ and $\chi_2$ production amplitudes which vanish…
Collider experiments have recently measured the production cross section of hard jets separated by a rapidity gap as a function of transverse momentum and gap size. We show that these measurements reveal the relative frequencies for the…
We investigate the inclusive production of double quarkonia ($J/\psi$, $\psi(2S)$, $\Upsilon$ mesons) in polarized hadron-hadron collisions, considering the kinematic configuration where the transverse momentum of each pair of bound states…
There are many outstanding discrepancies comparing the predictions of perturbative QCD and measurements of the rate of production and decay of heavy quark systems. The problems include the $J/\psi \to \rho \pi$ puzzle, leading charmed…
The exchange of gluons between heavy quarks produced in $e^+e^-$ interactions results in an enhancement of their production near threshold. We study QCD threshold effects in $\gamma\gamma$ collisions. The results are relevant to heavy quark…
We study the production of heavy quarkonium in association with an additional heavy pair. We argue that important contributions may come from phase space regions where three heavy fermions are separated by relative velocities much lower…
A model for the production of quarkonium states in the midrapidity region at RHIC and LHC energy range is presented which explores well understood properties of QCD only. An increase of the quarkonium hadronisation time with the initial…
Recent data from the Tevatron has revealed that the production rate of prompt charmonium at large transverse momentum is orders of magnitude larger than the best theoretical predictions of a few years ago. These surprising results can be…
Quarkonium production in high-energy proton (deuteron)-nucleus collisions is investigated in the color glass condensate framework. We employ the color evaporation model assuming that the quark pair produced from dense small-x gluons in the…
Color screening and regeneration are both hot medium effects on quarkonium production in high energy nuclear collisions. However, they affect in an opposite way the finally observed quarkonium spectra. Due to the competition of the two…
In this paper hadroproduction of charmonium states in polarized pp collisions is discussed. A thermal picture for the gluonic cloud of comovers is given making contact between the formalism and the measured unpolarized cross sections. The…
Quarkonium production in high-energy hadronic collisions is a useful tool to investigate fundamental aspects of Quantum Chromodynamics, from the proton and nucleus structure to deconfinement and the properties of the Quark Gluon Plasma…
We discuss the theory of inclusive production of heavy quarkonium, the comparison between theory and experiment, and the expected nuclear effects in cold nuclear targets. We also present predictions, based on Nonrelativistic QCD (NRQCD),…
Uncertainties in the next-to-leading-order calculations of heavy-quark ($Q$) production are investigated. Predictions for total cross sections, single-inclusive distributions of heavy quarks and heavy flavoured hadrons, as well as for…
We discuss the growing interest to measure associated-quarkonium production in a number of channels at the LHC. Whereas back-to-back production of quarkonium + isolated photon provides a unique way to extract gluon TMDs, observables such as…
We describe a precursor in heavy quarkonium production in terms of a coherent admixture of states of different color, spin, and angular momentum quantum numbers, and obtain the production amplitudes for different quarkonium bound states by…
We formulate the single transverse spin asymmetry in heavy quarkonium production in lepton-nucleon and nucleon-nucleon collisions in the non-relativistic limit. We find that the asymmetry is very sensitive to the production mechanism. The…