XXVIII International Workshop on Deep Inelastic Scattering and Related Subjects

Latest ALICE results on J/psi photoproduction in ultra-peripheral collisions at the LHC

25 Mar 2020, 11:52

17m

Brooklyn, NY

Contributed Talk Small-x, Diffraction and Vector Mesons Small-x, Diffraction and Vector Mesons

Speaker

Roman Lavička

Description

The high flux of quasi-real photons from fast moving lead ions at the LHC allows us to study photon-induced reactions in ultra-peripheral collisions (UPC) of Pb-Pb nuclei in a new kinematic regime. In addition, this flux makes it possible to study J/$\mathrm{\Psi }$ exclusive photoproduction off protons in p-Pb collisions at the LHC. Measuring the scattering angle of the produced vector meson one can compute the centre-of-mass energy of the photon-proton or photon-Pb scattering. This allows us to use these collisions to study the energy evolution of the gluon content of the target.

The newest ALICE results on vector meson photoproduction in UPC Pb-Pb in the forward and central rapidity region, and p-Pb collisions from LHC Run 2 are presented. These results provide new stringent tests for models of saturation and shadowing at small-x. The measurements are compared to the newest models of this process. In addition, prospects for heavy vector meson photoproduction measurements in LHC Run 3 and 4 will be presented.