Measurement of coherent exclusive $J/\psi \to {\mu }^{+}{\mu }^{-}$ production in ultraperipheral Pb+Pb collisions at $\sqrt{s_{\text{NN}}}=5.36$ TeV with the ATLAS detector

Abstract

The ATLAS experiment has performed a measurement of coherent exclusive $J/\psi \to {\mu }^{+}{\mu }^{-}$ production in ultraperipheral Pb+Pb collisions at $\sqrt{s_{\text{NN}}}=5.36$ TeV. The data was recorded at the Large Hadron Collider (LHC) during 2023, and corresponds to an integrated luminosity of 79 $\mu$b${}^{-1}$. Exclusive $J/\psi$ candidates were selected with a dedicated track-sensitive trigger based on the ATLAS transition radiation tracker. The analysis involves reconstruction of the dimuon invariant mass based on muon tracks from the inner detector, as the muon transverse momentum range of interest precludes the use of the standard muon reconstruction and identification algorithms. Differential cross sections are measured as a function of $J/\psi$ rapidity and are compared with theoretical predictions. After extrapolation to $\sqrt{s_{\text{NN}}}=5.02$ TeV, they are also compared with previous measurements performed by other experiments using data from LHC Run 2. While the results agree reasonably well with theoretical predictions, they are in tension with previous Run-2 results for the central rapidity region.

arXiv comment43 pages in total, author list starting page 27, 9 figures, 2 tables, published in JHEP. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/HION-2025-01/

References in corpus (19)

• The Physics of Ultraperipheral Collisions at the LHC
• An Impact Parameter Dipole Saturation Model
• Exclusive Vector Meson Production in Relativistic Heavy Ion Collisions
• STARlight: A Monte Carlo simulation program for ultra-peripheral collisions of relativistic ions
• Nuclear shadowing
• Leading twist nuclear shadowing phenomena in hard processes with nuclei
• Coherent Vector Meson Photoproduction with Nuclear Breakup in Relativistic Heavy Ion Collisions
• Photonuclear and Two-photon Interactions at High-Energy Nuclear Colliders
• Coherent and incoherent $J/\psi$ photonuclear production in an energy-dependent hot-spot model
• Evidence for nuclear gluon shadowing from the ALICE measurements of PbPb ultraperipheral exclusive J/ψ production
• Coherent photoproduction of vector mesons in heavy ion ultraperipheral collisions: Update for run 2 at the CERN Large Hadron Collider
• Disentangling coherent and incoherent quasielastic $J/\psi$ photoproduction on nuclei by neutron tagging in ultraperipheral ion collisions at the LHC
• Multiphoton Exchange Processes in Ultraperipheral Relativistic Heavy Ion Collisions
• Investigation of diffractive photoproduction of $J/\Psi$ in hadronic collisions
• Exclusive $J/\psi$ photoproduction in ultraperipheral Pb+Pb collisions at the LHC to next-to-leading order perturbative QCD
• Coherent photoproduction of $J/\psi$ in nucleus-nucleus collisions in the color dipole approach
• Photonuclear $J/\psi$ production at the LHC: proton-based versus nuclear dipole scattering amplitudes
• Energy dependent nuclear suppression from gluon saturation in exclusive vector meson production
• Elastic photon-initiated production at the LHC: the role of hadron-hadron interactions