@article{7cbc0b36eb284fe4b8068876f4a14885,
title = "Probing Small Bjorken-x Nuclear Gluonic Structure via Coherent J=ψ Photoproduction in Ultraperipheral Pb-Pb Collisions at √sNN = 5.02 TeV",
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.",
author = "{CMS Collaboration} and A. Tumasyan and W. Adam and Andrejkovic, {J. W.} and T. Bergauer and S. Chatterjee and K. Damanakis and M. Dragicevic and {Escalante Del Valle}, A. and Hussain, {P. S.} and M. Jeitler and N. Krammer and L. Lechner and D. Liko and I. Mikulec and J. Schieck and R. Sch{\"o}fbeck and D. Schwarz and M. Sonawane and S. Templ and W. Waltenberger and Wulz, {C. E.} and Darwish, {M. R.} and T. Janssen and T. Kello and {Van Mechelen}, P. and Bols, {E. S.} and J. D'Hondt and {De Moor}, A. and M. Delcourt and {El Faham}, H. and S. Lowette and A. Morton and D. M{\"u}ller and Sahasransu, {A. R.} and S. Tavernier and {Van Doninck}, W. and {Van Putte}, S. and D. Vannerom and B. Clerbaux and S. Dansana and {De Lentdecker}, G. and L. Favart and D. Hohov and J. Jaramillo and Joshi, {B. M.} and M. Krohn and D. Mahon and J. Mans and N. Strobbe and B. Marzocchi",
note = "Publisher Copyright: {\textcopyright} 2023 CERN, for the CMS Collaboration.",
year = "2023",
month = dec,
day = "29",
doi = "10.1103/PhysRevLett.131.262301",
language = "English (US)",
volume = "131",
journal = "Physical review letters",
issn = "0031-9007",
publisher = "American Physical Society",
number = "26",
}