The exclusive photoproduction of lepton pairs on nucleon and nucleus target
is investigated within the high energy color dipole approach, where the main
physical quantity is the dipole-target elastic scattering amplitude that
captures the main features of the dependence on atomic number A, on energy and
on momentum transfer t. These calculations are input in predictions for
electromagnetic interactions in pp and AA collisions to be measured at the LHC.Comment: 5 pages, 1 figure and 1 table. Contribution to the proceedings of
XXXVIII International Symposium on Multiparticle Dynamics (ISMD2008).
Hamburg, Germany, 15-20 September 200