The ALICE Zero Degree Calorimeter in pp physics

Abstract

ALICE is the dedicated heavy-ion experiment at the CERN LHC collider. The experiment main aim is to study the transition of hadronic matter to the deconfined plasma of quarks and gluons (QGP) predicted by Lattice QCD calculations. Proton-proton and proton-nucleus data will be used as reference. The ALICE Zero Degree Calorimeter system is made of two sets of forward hadronic calorimeters placed on both sides relative to the interaction point. Each set consists of a neutron and a proton calorimeter. The ZDC has been designed to trigger on the collision centrality in heavy-ion interactions. In proton-proton collisions they measure the energy flow of the leading neutrons and protons. Thanks to the forward rapidity region covered, they can be used to select different event topologies: minimum bias, non diffractive and diffractive events. Results from the 2009 run at s = 900 GeV as well as from 2010 data taking at s = 7 TeV are presented, putting the emphasis on the detector performance.