ARGO-YBJ: Physics results and detector stabilization

The ARGO-YBJ experiment at 4300 m above sea level on the Tibet plateau is a full-coverage array of Resistive Plate Chambers (RPCs) operated in streamer mode, covering a surface of 74×78 m2 surrounded by a guard ring. It was designed to detect extensive air showers generated by primary cosmic rays in the energy range from a few hundred GeV up to about 1 PeV. It has been running uninterruptedly with its complete layout since October 2007, providing results in γ - ray astrophysics and cosmic-ray physics. Some of the main results obtained by ARGO-YBJ in the study of TeV γ rays from Supernova Remnants and from Active Galactic Nuclei and in the study of the medium-scale cosmic-ray anisotropy will be described. We also discuss the results of a test which proves the feasibility of the control procedure devised to stabilize the response of the detector.