https://doi.org/10.1051/epjconf/202429610002
First study of the initial gluonic fluctuations using UPCs with ALICE
Institute of Nuclear Physics Polish Academy of Sciences, Radzikowskiego 152, 31-342 Kraków, Poland
* e-mail: adam.tomasz.matyja@cern.ch
Published online: 26 June 2024
Incoherent and dissociative J/ψ photoproduction is sensitive to fluctuations of the gluonic structure of the target. Thus, the measurement of Jψ photoproduction of the colliding hadron sheds light on the initial state of QCD and provides important constraints on the initial conditions used in hydrodynamical models of heavy-ion collisions. The first measurement of the transverse momentum dependence of both coherent and incoherent Jψ photoproduction in ultraperipheral Pb–Pb collisions at midrapidity is presented. These new results provide, a clear indication of subnucleonic fluctuations of the lead target. We also present the new measurement of dissociative Jψ photoproduction cross section as a function of energy, in p–Pb collisions at forward rapidity. Dissociative results do not show any indication of saturation and agree with previous data.
© The Authors, published by EDP Sciences, 2024
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