"Using the LHC as a photon collider"

Dr. Daniel Tapia Takaki
Institut de Physique Nucléaire d'Orsay (CNRS/IN2P3)
Université Paris-Sud


The strong electromagnetic fields surrounding the protons and nuclei, accelerated by the LHC, lead to very large cross sections for photon-induced processes. For example, the photonuclear cross section for certain processes in Pb-Pb collisions is larger than the total hadronic one of about 8 b. This makes the LHC the world's most poweful collider not only for protons and lead ions but also for photon-photon and photon-hadron collisions. This seminar will review the physics of ultra-peripheral collisions where these photo-induced reactions take place. It will then give ALICE results on coherent J/psi photoproduction and will also birefly cover the prospects of the forthcoming proton-lead run.