Invited Talk: Ludovico PontevorvoParticle detectors enabling high energy physics discoveries:The ATLAS muon spectrometer and electromagnetic calorimeter

In this talk I will present the Physics considerations that drove the design of the ATLAS detector. In particular I will focus on the production and decays of the, at the time unknown, Higgs particles in Photons and leptons. I will describe the trigger strategies adopted and the main detectors that allowed the discovery of the Higgs particle in 2012. The Inner detector, the Muon Spectrometer and the electromagnetic calorimeter played a central role in the Higgs discovery, allowing a very precise measurement of Photons (electromagnetic calorimeter) and Leptons (Muon and Electrons) combining the Inner Tracker and the Muon spectrometer information. I will describe these systems giving particular emphasis to the muon spectrometer construction and operation. Finally, I will briefly present the upgrade plans for the ATLAS detector that will allow the experiment to continue to take data at the Hi- Luminosity LHC up to early 2040s.