We study the peripheral ion collisions at LHC energies in which a nucleus is
excited to the discrete state and then emits γ-rays. Large nuclear
Lorenz factor allows to observe the high energy photons up to a few ten GeV and
in the region of angles of a few hundred micro-radians around the beam
direction. These photons can be used for tagging the events with particle
production in the central rapidity region in the ultra-peripheral collisions.
For that it is necessary to have an electromagnetic detector in front of the
zero degree calorimeter in the LHC experiments.Comment: 14 pages, 6 Postscript figure