Description
The ALICE experiment is equipped with a broad range of
detectors which allows one to study photon-induced and diffractive
processes characterized by large rapidity gaps. The forward detectors of
ALICE are used to detect rapidity gaps and to trigger on diffraction
events. Special attention is given to double gap events, dominated by
central-exclusive processes, because of the high-performance tracking
and particle identification capabilities of the central detectors. The
study of such processes helps in understanding the dynamics of Pomeron
exchanges and its connection to soft QCD. Since Pomeron exchanges are
gluon-rich processes the enhanced glueball producion is expected:
resonance spectrum study is to be performed in order to seach for
possible glueball candidates. ALICE results from Run 1 & 2 and the
perspectives for LHC Run 3 & 4 on diffractive measurements are discussed
in the talk.
Photon-induced reactions are studied in ultra-peripheral p-Pb and Pb-Pb
collisions because of the high photon flux from lead ions, which is
proportional to the square of the ion charge. Measurements of vector
meson photoproduction in ultra-peripheral collisions are of particular
interest, allowing one to probe the gluon PDFs and study poorly known
nuclear gluon shadowing effects in a wide range of Bjorken-x. The ALICE
results on vector meson photoproduction are presented and perspectives
for future measurements are outlined.
