Coherent J/ψ photoproduction at forward rapidity in ultra-peripheral Pb–Pb collisions at sNN=5.02 TeV

Summary, in English

The ALICE collaboration performed the first rapidity-differential measurement of coherent J/ψ photoproduction in ultra-peripheral Pb–Pb collisions at a center-of-mass energy sNN=5.02 TeV. The J/ψ is detected via its dimuon decay in the forward rapidity region (−4.0<y<−2.5) for events where the hadronic activity is required to be minimal. The analysis is based on an event sample corresponding to an integrated luminosity of about 750 μb−1. The cross section for coherent J/ψ production is presented in six rapidity bins. The results are compared with theoretical models for coherent J/ψ photoproduction. These comparisons indicate that gluon shadowing effects play a role in the photoproduction process. The ratio of ψ′ to J/ψ coherent photoproduction cross sections was measured and found to be consistent with that measured for photoproduction off protons. © 2019 The Author

• Author: S Acharya; Jonatan Adolfsson; Peter Christiansen; Martin Ljunggren; Adrian Nassirpour; Anders Oskarsson; Tuva Richert; Omar Vazquez Rueda; David Silvermyr; Evert Stenlund; N Zurlo
• Department/s: Particle and nuclear physics; eSSENCE: The e-Science Collaboration
• Publishing year: 2019
• Language: English
• Publication/Series: Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
• Volume: 798
• Links: http://dx.doi.org/10.1016/j.physletb.2019.134926
• Document type: Journal article
• Publisher: Elsevier
• Topic: Subatomic Physics
• Status: Published
• ISBN/ISSN/Other: ISSN: 0370-2693