相关论文: Possible solution of the J/psi production puzzle
I review recent developments in theoretical understandings of J/psi productions in various processes at Tevatron, B decay and J/psi photoproduction including the color-octet mechanism.
We have studied the J/psi suppression in 158 GeV/c Pb+Pb collisions at CERN SPS. J/psi production is assumed to be a two step process, (i) formation of c bar{c} pair, which is accurately calculable in QCD and (ii) formation of J/psi meson…
Recent measurements of J/psi production in e^+ e^- colliders pose a challenge to the NRQCD factorization theorem for quarkonium production. Discrepancies between leading order calculations of color-octet contributions and the momentum…
We demonstrate that the recent studies of J/psi-pair production by CMS at the LHC and by D0 at the Tevatron reveal the presence of different production mechanisms in different kinematical regions. We find out that next-to-leading-order…
The production of J/psi mesons is studied with the LHCb detector using data from pp collisions at sqrt(s)=2.76 TeV corresponding to an integrated luminosity of 71 nb^-1. The differential cross-section for inclusive J/psi production is…
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…
Electro-production of several pentaquark states is investigated in this paper. eSTARlight package is adapted to study the electro-production of $J/\psi$ and $\Upsilon (1S)$ via pentaquark $P_c$ and $P_b$ resonance channels in $e p \to e…
Approximately taking into account the higher-order effects due to multiple-gluon initial-state radiation, we extract from the latest Tevatron data of prompt J/psi hadroproduction the leading colour-octet matrix elements within the…
We present a rigorous next-to-leading order analysis of J/psi yield and polarization within the factorization theorem of nonrelativistic QCD (NRQCD). To the orders considered, this framework depends on three free parameters, the color-octet…
We study the inclusive production of J/psi and psi(2S) mesons originating from the decays of bottom-flavored hadrons produced in p anti-p collisions at the Fermilab Tevatron and in pp collisions at the CERN LHC. We work at next-to-leading…
Hadrons produced in high-energy heavy-ion collisions can suppress the production of J/psi and other charmonium states by charmonium spontaneous dissociation as the hot hadronic environment alters the interaction between the charm quark and…
We investigate near-threshold $J/\psi$ photoproduction off the nucleon, focusing on hadronic rescattering effects induced by open-charm meson-baryon intermediate states. Beyond the conventional Pomeron-exchange mechanism, the $\bar…
The process pp--> W + J/psi provides a powerful probe of the production mechanism of charmonium in hadronic collisions, and is also sensitive to multiple parton interactions in the colliding protons. Using the 2011 ATLAS dataset of 4.5 fb-1…
The photoproduction of the $J/\psi$ off the proton is believed to deepen our understanding of various physics issues. On the one hand, it is proposed to provide access to the origin of the proton mass, based on the QCD multipole expansion.…
Production of open and hidden charm hadrons in heavy ion collisions is considered within the statistical coalescence model. Charmed quarks and antiquarks are assumed to be created at the initial stage of the reaction and their number is…
We study the processes, $e^- e^+ \rightarrow \gamma^* \gamma^* \rightarrow J/\psi +J/\psi$, and $e^- e^+ \rightarrow \gamma^* \gamma^* \rightarrow \eta_c+ \eta_c$ at $\sqrt{s}=10.6$ GeV in the framework of $4\times 4$ Bethe-Salpeter…
Several fixed-target experiments reported J/$\psi$ and $\Upsilon$ polarization measurements, as functions of Feynman $x$ ($x_{\rm F}$) and transverse momentum ($p_{\rm T}$), in three different polarization frames, using different…
Calculations are presented for incoherent $J/\psi$ electroproduction from the deuteron at JLab energies, including the effects of $J/\psi$-nucleon rescattering in the final state, in order to determine the feasibility of measuring the…
New, more precise data on diffractive J/psi photoproduction and on exclusive J/psi production in the process pp -> p + J/psi + p at the LHC allow a better constraint on the low-x gluon distribution in the domain of relatively low scales Q^2…
We investigate the theoretical uncertainty on the predictions for the photoproduction of J/psi and Upsilon states in the proton-nucleus and nucleus-nucleus collisions at the LHC within the color dipole formalism. Predictions for the…