Abstract

The Large Hadron Collider LHC at the European Laboratory for Particle Physics CERN near Geneva will deliver particle collisions at the highest energy ever achieved in a laboratory. After more than 15 years of design and construction efforts the LHC and its experiments are finally starting operation. Besides the giant accelerator, which is installed in a ring tunnel of 27 km length about 100 m underground, the no less impressive and complex detectors are ready for data taking. After a brief introduction to the LHC , a general overview of one of the key-experiments, ATLAS , will be given. The LHC will allow ATLAS to study for the first time fundamental physics phenomena as they occurred very shortly after the Big Bang. ATLAS will address questions like: why have particles a mass, what is the non-visible dark matter in the Universe, are there more than four dimensions in Nature, what are the smallest building blocks of matter? The expectations for new discoveries are high, since decades physicists are eagerly awaiting this exploratory step into the unknown. The ATLAS detector has been developed and constructed by a world-wide collaboration, and a team from the Cavendish Laboratory has contributed to the project since its conception some 20 years ago. Some highlights of the construction and commissioning of the detector will be illustrated, as well as examples of anticipated discovery signals.

Speaker: Peter Jenni (CERN, Spokesperson ATLAS Collaboration)