Coherent $J/\psi$ and ${\psi }^{\prime }$ photoproduction at midrapidity in ultra-peripheral Pb-Pb collisions at $\sqrt{s_{\mathrm{NN}}}=5.02$ TeV

Abstract

The coherent photoproduction of $J/\psi$ and ${\psi }^{\prime }$ 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 central rapidity region for events where the hadronic interactions are strongly suppressed. The $J/\psi$ is reconstructed using the dilepton ($l^{+}{l}^{-}$) and proton-antiproton decay channels, while for the ${\psi }^{\prime }$, the dilepton and the $l^{+}{l}^{-}{\pi }^{+}{\pi }^{-}$ decay channels are studied. The analysis is based on an event sample corresponding to an integrated luminosity of about 233 ${\mu b}^{-1}$. The results are compared with theoretical models for coherent $J/\psi$ and ${\psi }^{\prime }$ photoproduction. The coherent cross section is found to be in a good agreement with models incorporating moderate nuclear gluon shadowing of about 0.65 at a Bjorken-$x$ of around $6\times 10^{-4}$, such as the EPS09 parametrization, however none of the models is able to fully describe the rapidity dependence of the coherent $J/\psi$ cross section including ALICE measurements at forward rapidity. The ratio of ${\psi }^{\prime }$ to $J/\psi$ coherent photoproduction cross sections was also measured and found to be consistent with the one for photoproduction off protons.

29 pages, 6 captioned figures, 4 tables, authors from page 23, published version, figures at http://alice-publications.web.cern.ch/node/6778

References in corpus (9)

• EPS09 - a New Generation of NLO and LO Nuclear Parton Distribution Functions
• The Physics of Ultraperipheral Collisions at the LHC
• J/Psi production in ultraperipheral Pb+Pb and p+Pb collisions at energies available at the CERN Large Hadron Collider
• Imaging the nucleus with high-energy photons
• Energy dependence of dissociative $J/\psi$ photoproduction as a signature of gluon saturation at the LHC
• Investigation of diffractive photoproduction of $J/\Psi$ in hadronic collisions
• Theoretical uncertainties in exclusive electroproduction S-wave heavy quarkonia
• Coherent photoproduction of $J/\psi$ in nucleus-nucleus collisions in the color dipole approach
• D-wave effects in heavy quarkonium production in ultraperipheral nuclear collisions

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