Alice Ohlson
Senior lecturer
First measurement of the |t|-dependence of coherent J/ψ photonuclear production
Author
Summary, in English
The first measurement of the cross section for coherent J/ψ photoproduction as a function of |t|, the square of the momentum transferred between the incoming and outgoing target nucleus, is presented. The data were measured with the ALICE detector in ultra-peripheral Pb–Pb collisions at a centre-of-mass energy per nucleon pair sNN=5.02TeV with the J/ψ produced in the central rapidity region |y|<0.8, which corresponds to the small Bjorken-x range (0.3−1.4)×10−3. The measured |t|-dependence is not described by computations based only on the Pb nuclear form factor, while the photonuclear cross section is better reproduced by models including shadowing according to the leading-twist approximation, or gluon-saturation effects from the impact-parameter dependent Balitsky–Kovchegov equation. These new results are therefore a valid tool to constrain the relevant model parameters and to investigate the transverse gluonic structure at very low Bjorken-x. © 2021 The Author(s)
Department/s
- Particle and nuclear physics
- eSSENCE: The e-Science Collaboration
Publishing year
2021
Language
English
Publication/Series
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
Volume
817
Document type
Journal article
Publisher
Elsevier
Topic
- Subatomic Physics
Status
Published
ISBN/ISSN/Other
- ISSN: 0370-2693