Hakobyan, H., Hamdi, A., Han, S. et al. (81 more authors) (2019) First Measurement of Near-Threshold J /ψ Exclusive Photoproduction off the Proton. Physical Review Letters. 072001. ISSN 1079-7114
Abstract
We report on the measurement of the γp→J/ψp cross section from Eγ=11.8 GeV down to the threshold at 8.2 GeV using a tagged photon beam with the GlueX experiment. We find that the total cross section falls toward the threshold less steeply than expected from two-gluon exchange models. The differential cross section dσ/dt has an exponential slope of 1.67±0.39 GeV-2 at 10.7 GeV average energy. The LHCb pentaquark candidates Pc+ can be produced in the s channel of this reaction. We see no evidence for them and set model-dependent upper limits on their branching fractions B(Pc+→J/ψp) and cross sections σ(γp→Pc+)×B(Pc+→J/ψp).
Metadata
Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2019 American Physical Society |
Dates: |
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Institution: | The University of York |
Academic Units: | The University of York > Faculty of Sciences (York) > Physics (York) |
Depositing User: | Pure (York) |
Date Deposited: | 03 Sep 2019 15:50 |
Last Modified: | 06 Dec 2023 13:17 |
Published Version: | https://doi.org/10.1103/PhysRevLett.123.072001 |
Status: | Published |
Refereed: | Yes |
Identification Number: | https://doi.org/10.1103/PhysRevLett.123.072001 |
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