Speaker
Description
The ultra-peripheral collisions (UPCs) of relativistic heavy-ion collisions provide a unique opportunity to study the photon induced interactions
at the LHC in new kinematic regimes.
The ALICE experiment has measured the coherent photo-nuclear production of the $\rho^{0}$ and J/$\psi$ vector mesons in UPCs.
The measurement of $\rho$ vector meson is an excellent tool to study nuclear shadowing effects and the approach to the black-disc limit of QCD, while the J/$\psi$ measurement is also a good tool to study the nuclear shadowing and saturation effects at low-x.
In this contribution, recent results obtained with the data from the LHC Run2 will be presented.
The first measurement of the cross section of the $\rho^{0}$ mesons in Xe-Xe at $\sqrt{s_{NN}}$ = 5.44 TeV and Pb-Pb UPCs at $\sqrt{s_{NN}}$ = 5.02 TeV, and the cross section of the J/$\psi$ mesons and its t-dependence in Pb-Pb UPCs at $\sqrt{s_{NN}}$ = 5.02 TeV will be reported.
These results are compared with various model predictions in order to improve our phenomenological understanding of the UPCs.
