TY  - INPR
T1  - Observation of strong nuclear suppression in exclusive J/ψ photoproduction in Au+Au ultra-peripheral collisions at RHIC
T2  - arXiv
N2  - We report a measurement of exclusive J/ψ photoproduction in Au+Au ultra-peripheral collisions at sNN−−−√=200 GeV using the STAR detector. For the first time, i) the rapidity correlation between J/ψ photoproduction and neutron emission from nuclear breakups has been experimentally measured; ii) nuclear suppression factors are measured for both the coherent and incoherent J/ψ production. At photon-nucleon center-of-mass energy of 25.0 GeV, the coherent and incoherent J/ψ cross sections of Au nuclei are found to be 71±10% and 36±7%, respectively, of that of free protons. The stronger suppression observed in the incoherent production provides a new experimental handle to study the initial-state parton density in heavy nuclei. Data are compared with theoretical models quantitatively.
KW  - ultra-peripheral collision
KW  - vector meson production
KW  - nuclear parton modification
Y1  - 2023
UR  - http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/86185
UR  - https://nbn-resolving.org/urn:nbn:de:hebis:30:3-861856
UR  - https://arxiv.org/abs/2311.13637v2
IS  - 2311.13637v2
PB  - arXiv
ER  -