相关论文: Quarkonium polarization in low-$p_{\rm T}$ hadro-p…
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…
This talk presents a review of recent results for quarkonium production at the LHC from ATLAS, CMS, LHCb, and ALICE. Production cross sections for $J/\psi$, $\psi(2S)$, and $\Upsilon(mS)$, and production ratios for $\chi_{c,bJ}$ are found…
I compare current approaches to quarkonium production with regard to what they tell us about quarkonium polarization. Predictions for $J/\psi$ polarization in hadron-hadron and photon-hadron collisions are summarized.
The polarization of inclusive J/$\psi$ and $\Upsilon(1{\rm S})$ produced in Pb-Pb collisions at $\sqrt{s_{\rm{NN}}}=5.02$ TeV at the LHC is measured with the ALICE detector. The study is carried out by reconstructing the quarkonium through…
Both charm and bottom quarks form nonrelativistic bound states analogous to positronium. The J/psi and psi(2S) charmonium states and the first three Upsilon(nS) bottomonium states, all spin-triplet S-wave quarkonium states below…
Polarization measurements are the best instrument to understand how quark and antiquark combine into the different quarkonium states, but no model has so far succeeded in explaining the measured J/psi and Upsilon polarizations. On the other…
Photonuclear reactions are induced by the strong electromagnetic field generated by ultrarelativistic heavy-ion collisions. These processes have been extensively studied in ultraperipheral collisions, where the impact parameter is larger…
We review the current status of heavy quarkonium production phenomenology based on nonrelativistic effective field theories, focusing on spin-triplet $S$-wave states such as $J/\psi$, $\psi(2S)$, and $\Upsilon$. We present some…
The polarization of quarkonium states produced in hadron collisions exhibits strong non-perturbative effects - for example, at small transverse momentum $p_t$ charmonia appear unpolarized, in sharp contradiction to the predictions of…
The measurement of polarization serves as an important probe to investigate the production mechanism of quarkonia, the bound state of heavy quark anti-quark (charm or bottom) pairs, in hadronic collisions. In experimental invesigations, the…
Photonuclear reactions are induced by the strong electromagnetic field generated by ultrarelativistic heavy ions. These processes have been extensively studied in ultraperipheral collisions. In recent years, the observation of coherent…
The production of J /{\psi} and {\Upsilon} mesons is studied in pp collisions at \surds = 7 TeV with the CMS experiment at the LHC. The J /{\psi} measurement is based on a dimuon sample corresponding to an integrated luminosity of 314…
The polarizations of Y(nS) (n=1,2,3) and prompt J/\psi and \psi(2S), as well as the differential cross section of the Y(nS), are measured in proton-proton collisions at sqrt(s) = 7 TeV, using a dimuon data sample collected by the CMS…
We present a measurement of the polarization observed for bottomonium states produced in p-Cu collisions at sqrt(s)=38.8 GeV. The angular distribution of the decay dimuons of the Upsilon(1S) state show no polarization at small xF and pT but…
Studies of quarkonium production in heavy-ion collisions can be used for probing QGP properties. The suppression and regeneration of bound quarkonium states is sensitive to the medium properties. Modifications of the quarkonium polarization…
Production mechanisms for quarkonium states in hadronic collisions remain difficult to understand. The decay angular distributions of J/$\psi$ or $\Upsilon(nS)$ states into $\mu^+ \mu^-$ final states are sensitive to the matrix elements in…
We show that the production of J/psi or Upsilon pairs in unpolarised pp collisions is currently the best process to measure the momentum-distribution of linearly-polarised gluons inside unpolarised protons through the study of azimuthal…
Photon-photon reactions and the production of J/$\psi$ meson through photonuclear reactions have been extensively studied in ultra-peripheral heavy-ion collisions, in which the impact parameter is larger than twice the nuclear radius. In…
More than 30 years after the discovery of the J/psi, its production mechanism is still poorly understood. With the LHC data it will be possible to study quarkonia up to very high transverse momenta and with high statistics. In this note we…
CDF has obtained new results on quarkonium production in p\bar{p} collisions at \sqrt{s} = 1.8 TeV. We report on measurements of Upsilon meson production, Upsilon(1S) production from Chi_b feeddown, and the production polarization of…