Speaker
Daniele De Gruttola
(University and INFN of Salerno - CERN)
Description
When two relativistic nuclei collide with impact parameter larger than twice their radius (b>2R_A), they may interact in several ways: nuclear excitation with neutron emission, two-photon exchange, coherent production of vector mesons with pomeron or gluon exchange. These events are usually referred as Ultra Peripheral Collisions (UPC). A relevant process is the production of vector mesons
containing heavy flavours: this is a powerful tool to study the gluon distribution function in the nuclei, up to x as low as 10^-4. In this presentation we show the performance of the ALICE detector in the search for J/psi produced in UPC events during the first LHC Pb-Pb run atsqrt(s_NN)=2.76 TeV. The total cross section for this process is a small fraction of the total Pb-Pb cross section, therefore dedicated triggers have been used to tag these events both in the barrel and in the forward muon arm. The details of the data analysis, the cut optimization and the first J/psi candidate events are shown.
Primary author
Daniele De Gruttola
(University and INFN of Salerno - CERN)
