@article{10902/38544,
year = {2025},
month = {9},
url = {https://hdl.handle.net/10902/38544},
abstract = {Incoherent J/psi photoproduction in heavy ion ultraperipheral collisions (UPCs) provides a sensitive
probe of localized, fluctuating gluonic structures within heavy nuclei. This Letter reports the first
measurement of the photon-nucleon center-of-mass energy (WyN) dependence of this process in PbPb
UPCs at a nucleon-nucleon center-of-mass energy of 5.02 TeV, using 1.52 nb-1 of data recorded by the
CMS experiment. The measurement covers a wide WyN range of (almost)40-400 GeV, probing gluons carrying a fraction x of nucleon momentum down to an unexplored regime of 6.5 × 10-5. Compared to baseline
predictions neglecting nuclear effects, the measured cross sections exhibit significantly greater suppression
at lower x. Additionally, the ratio of incoherent to coherent photoproduction is found to be constant across
the probed WyN and x range, disfavoring the establishment of the black disk limit. This Letter provides
critical insights into the x-dependent evolution of fluctuating gluonic structures within nuclei and calls for
further advancements in theoretical models incorporating nuclear shadowing and gluon saturation.},
organization = {We congratulate our colleagues in the CERN accelerator departments for the excellent performance of the LHC and thank the technical and administrative staffs at CERN and at other CMS institutes for their contributions to the success of the CMS effort. In addition, we gratefully acknowledge the computing centers and personnel of the Worldwide LHC Computing Grid and other centers for delivering so effectively the computing infrastructure essential to our analyses. Finally, we acknowledge the enduring support for the construction and operation of the LHC, the CMS detector, and the supporting computing infrastructure provided by the following funding agencies: SC (Armenia), BMBWF and FWF (Austria); FNRS and FWO (Belgium); CNPq, CAPES, FAPERJ, FAPERGS, and FAPESP (Brazil); MES and BNSF (Bulgaria); CERN; CAS, MoST, and NSFC (China); MINCIENCIAS (Colombia); MSES and CSF(Croatia); RIF (Cyprus); SENESCYT (Ecuador); ERC PRG, RVTT3 and MoER TK202 (Estonia); Academy of Finland, MEC, and HIP (Finland); CEA and CNRS/IN2P3 (France); SRNSF (Georgia); BMBF, DFG, and HGF (Germany); GSRI (Greece); NKFIH (Hungary); DAE and DST (India); IPM (Iran); SFI (Ireland); INFN (Italy); MSIP and NRF (Republic of Korea); MES (Latvia); LMTLT (Lithuania); MOE and UM (Malaysia); BUAP,CINVESTAV,CONACYT,LNS,SEP,andUASLPFAI (Mexico); MOS (Montenegro); MBIE (New Zealand); PAEC(Pakistan); MES andNSC(Poland); FCT(Portugal); MESTD(Serbia); MICIU/AEI and PCTI (Spain); MOSTR (Sri Lanka); Swiss Funding Agencies (Switzerland); MST (Taipei); MHESI and NSTDA (Thailand); TUBITAK and TENMAK (Turkey); NASU (Ukraine); STFC (United Kingdom); DOE and NSF (USA).},
publisher = {American Physical Society},
publisher = {Physical Review Letters, 2025, 135(11), 112301},
title = {Probing gluon fluctuations in nuclei with the first energy-dependent measurement of incoherent J/psi photoproduction in ultraperipheral PbPb collisions},
author = {Chekhovsky, V. and Hayrapetyan, A. and Makarenko, V. and Blanco Fernández, Sergio and Cabrillo Bartolomé, José Ibán and Calderón Tazón, Alicia and Duarte Campderros, Jorge and Fernández García, Marcos and Gómez Gramuglio, Gervasio and Lasaosa García, Clara and López Ruiz, Rubén and Martínez Rivero, Celso and Martínez Ruiz del Árbol, Pablo and Matorras Weinig, Francisco and Matorras Cuevas, Pablo and Navarrete Ramos, Efrén and Piedra Gómez, Jonatan and Scodellaro, Luca and Vila Álvarez, Iván and Vizán García, Jesús Manuel},
}