Speaker
Description
The ALICE Collaboration has studied photonuclear interactions in ultra-peripheral heavy-ion collisions to probe gluon dynamics of protons and nuclei in a new kinematic regime at the LHC.
Several new measurements will be presented, including the coherent J/ψ photoproduction cross section, measured as a function of the Mandelstam |t|, which provides constraints of models that consider the transverse profile of the target at very low Bjorken-x.
The polarization of coherent J/psi photoproduction has been measured
for the first time and found to be compatible with transverse polarization.
Both exclusive and, for the first time at LHC, dissociative J/ψ photoproduction cross section have been measured in proton targets.
Finally, the energy dependence of the photonuclear cross section is presented for photon-nuclear energies from 17 GeV up to 920 GeV and for the Bjorken-x down to $10^{−5}$, exploring a new regime of super dense gluons.
