@article{10902/32867,
year = {2023},
month = {12},
url = {https://hdl.handle.net/10902/32867},
abstract = {Quasireal photons exchanged in relativistic heavy ion interactions are powerful probes of the gluonic structure of nuclei. The coherent J=ψ photoproduction cross section in ultraperipheral lead-lead collisions is measured as a function of photon-nucleus center-of-mass energies per nucleon (WPb γN) over a wide range of 40 < WPb γN < 400 GeV. Results are obtained using data at the nucleon-nucleon center-of-mass energy of 5.02 TeV collected by the CMS experiment at the CERN LHC, corresponding to an integrated luminosity of 1.52 nb−¹. The cross section is observed to rise rapidly at low WPb γN, and plateau above WPb γN ≈ 40 GeV, up to 400 GeV, entering a new regime of small Bjorken-x (≈6 × 10−⁵) gluons being probed in a heavy nucleus. The observed energy dependence is not predicted by current quantum chromodynamic models.},
organization = {Individuals were supported by the National Science Center (Poland), Grants No. 2015/19/N/ST2/02697 and No. 2018/28/T/ST2/00199.},
publisher = {American Physical Society},
publisher = {Physical Review Letters, 2023, 131(26), 262301},
title = {Probing small Bjorken-x nuclear gluonic structure via coherent J=Ψ photoproduction in ultraperipheral Pb-Pb collisions at √sNN = 5.02 TeV},
author = {Tumasyan, A. and Brochero Cifuentes, Javier Andrés and Cabrillo Bartolomé, José Iban and Calderón Tazón, Alicia and Duarte Campderros, Jorge and Fernández García, Marcos and Fernández Madrazo, Celia and Gómez Gramuglio, Gervasio and Lasaosa García, Clara and Martínez Rivero, Celso and Martínez Ruiz del Árbol, Pablo and Matorras Weinig, Francisco and Matorras Cuevas, Pablo and Piedra Gómez, Jonatan and Prieëls, Cedric and Scodellaro, Luca and Vila Álvarez, Iván  and Vizán García, Jesús Manuel},
}