相关论文: J/\psi Photo- and DIS Production via Nonlinear Evo…
The coherent J/$\psi$ photoproduction cross section is measured for the first time at midrapidity in peripheral to semicentral Pb$-$Pb collisions at $\sqrt{s_{\rm NN}} = 5.02$ TeV. The centrality differential cross section ${\rm d} \sigma/…
We present predictions for differential cross sections for the reaction $\gamma p \to \Phi p$ and give an outlook to which extent our calculations may be generalized to the photoproduction of $J/\Psi$ mesons. Our results are obtained within…
We calculate the Sivers and $\cos2\phi$ azimuthal asymmetries in $J/\psi$ production in polarized and unpolarized semi-inclusive $ep$ collision respectively, using the formalism based on transverse momentum dependent parton distributions…
In this work, we revise the conventional description of J/Psi(1S), Y(1S), Psi'(2S) and Y'(2S) elastic photo- and electroproduction off a nucleon target within the color dipole picture and carefully study various sources of theoretical…
We present the first measurement of the production of the $\phi$ meson in 30 GeV proton-nucleus interactions on carbon and copper targets via the di-electron decay channel. The measurement was conducted at the high-momentum beamline of the…
In order to understand the J/psi suppression arising from the possible occurrence of the quark-gluon plasma in high-energy heavy-ion collisions, it is necessary to have a comprehensive picture how the J/psi and its precursors are produced,…
We show that nuclear sigma, omega, and pi mesons can contribute coherently to enhance the electroproduction cross section on nuclei for longitudinal virtual photons at low Q^2 while depleting the cross section for transverse photons. We are…
A study of the angular distributions of leptons from decays of J/psi's produced in p-C and p-W collisions at sqrt{s}=41.6 GeV has been performed in the Feynman-x region -0.34 < x_F < 0.14 and for transverse momentum up to 5.4 GeV/c. The…
The production of J/Psi mesons in gamma gamma collisions allows for a test of factorization in color-octet processes as predicted by NRQCD and observed at the Tevatron. We calculate the cross sections for J/Psi production with direct and…
The production of $J/\psi$-pairs as a possible measure of the polarized gluon distribution $\Delta G(x)$ is studied for proton--nucleon collisions at $\sqrt{s} =40\;\mbox{GeV}^2$ (HERA-$\vec{{\rm N}}$). Possibilities of reconstructing the…
An exclusive coherent diffractive $J/\psi$ production dataset from HERA, covering a large kinematic range in the photon virtuality $Q^2$, the squared momentum transfer $t$, and the photon-proton center-of-mass energy $W$, has been analyzed…
Data on J/psi production in inelastic proton-proton, proton-nucleus and nucleus-nucleus interactions at 158 A GeV are analyzed and it is shown that the ratio of mean multiplicities of J/psi mesons and pions is the same for all these…
We investigate the exclusive photoproduction of $J/\psi$-mesons in ultraperipheral heavy ion collisions in the color dipole approach. We first test a number of dipole cross sections fitted to inclusive $F_2$-data against the total cross…
Hybrid/exotic meson spectroscopy searches at Jefferson Lab require the accurate theoretical description of the production mechanism in peripheral photoproduction. We develop a model for $\pi\Delta$ photoproduction at high energies ($5 \leq…
Protons and antiprotons at collider energies are a source of high energy Weizs\"acker--Williams photons. This may open a possibility to study exclusive photoproduction of heavy vector mesons at energies much larger than possible at the HERA…
We systematically investigate the production of $J/\psi + \gamma$ in $\gamma\gamma$ collisions within nonrelativistic QCD (NRQCD) factorization, with the direct-photon channel calculated specifically up to the next-to-leading order in…
The cross section for coherent photonuclear production of J/$\psi$ is presented as a function of the electromagnetic dissociation (EMD) of Pb. The measurement is performed with the ALICE detector in ultra-peripheral Pb-Pb collisions at a…
The photo-production of $\phi$ mesons from Li, C, Al, and Cu at forward angles has been measured at $E_gamma$=1.5--2.4 GeV. The number of events for incoherent phi photo-production is found to have a target mass number dependence of…
Based on the factorization framework of nonrelativistic quantum chromodynamics, we study the associated $J/\psi+c+\bar{c}$ photoproduction process at next-to-leading order in $\alpha_s$ and leading order in the velocity expansion. The total…
Elastic and proton-dissociative photoproduction of $\rho^0$, $\phi$ and $J/\psi$ vector mesons ($\gamma p\to Vp$, $\gamma p\to VN$, respectively) have been measured in e^+p interactions at HERA up to -t=3 GeV$^2$, where t is the…