Khachatryan, V., Sirunyan, A.M., Tumasyan, A. et al. (95 more authors) (2017) Coherent J/ψ photoproduction in ultra-peripheral PbPb collisions at s<inf>NN</inf>=2.76TeV with the CMS experiment. Physics Letters B, 772. pp. 489-511. ISSN 0370-2693
Abstract
The cross section for coherent J/ψ photoproduction accompanied by at least one neutron on one side of the interaction point and no neutron activity on the other side, X n 0 n , is measured with the CMS experiment in ultra-peripheral PbPb collisions at s NN =2.76TeV. The analysis is based on a data sample corresponding to an integrated luminosity of 159μb −1 , collected during the 2011 PbPb run. The J/ψ mesons are reconstructed in the dimuon decay channel, while neutrons are detected using zero degree calorimeters. The measured cross section is dσ X n 0 n coh /dy(J/ψ)=0.36±0.04(stat)±0.04(syst) mb in the rapidity interval 1.8 < |y| < 2.3. Using a model for the relative rate of coherent photoproduction processes, this X n 0 n measurement gives a total coherent photoproduction cross section of dσ coh /dy(J/ψ)=1.82±0.22(stat)±0.20(syst)±0.19(theo) mb. The data strongly disfavor the impulse approximation model prediction, indicating that nuclear effects are needed to describe coherent J/ψ photoproduction in γ+Pb interactions. The data are found to be consistent with the leading twist approximation, which includes nuclear gluon shadowing.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2017 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). |
Keywords: | CMS; Physics; Heavy ion collisions; Ultra-peripheral collisions; UPC; J/Psi |
Dates: |
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Institution: | The University of Sheffield |
Academic Units: | The University of Sheffield > Faculty of Science (Sheffield) > Department of Physics and Astronomy (Sheffield) |
Depositing User: | Symplectic Sheffield |
Date Deposited: | 31 Oct 2017 09:48 |
Last Modified: | 31 Oct 2017 09:48 |
Published Version: | https://doi.org/10.1016/j.physletb.2017.07.001 |
Status: | Published |
Publisher: | Elsevier |
Refereed: | Yes |
Identification Number: | 10.1016/j.physletb.2017.07.001 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:123264 |