ATLAS Upgrades towards the High Luminosity LHC: extending the discovery potential

ATLAS has successfully collected 5.25 and 21.7 fb−1 during LHC run I at √s = 7 and 8 TeV, respectively. However, the LHC planning for the years to come, with a foreseen delivered lumi- nosity up to 3000 fb−1 at √s = 14 TeV, is a great challenge for the detectors. ATLAS has already started a staged upgrade programme Involving most of the subsystems, in order to exploit the full physics accessible with the expected luminosity increase. This paper describes the ATLAS upgrade plans together with the expected detector performances and physics capabilities.