Precision Experiments at the Tera scale

Full text: Physics at center-of-mass energies in the TeV range aims at fundamental questions of micro and macrocosm. First signs are expected from pp collisions at the LHC. However, a deeper understanding requires precision measurements which are attainable only in e-e+ collisions at a linear collider. Two worldwide projects are in friendly competition: more advanced is the 1 TeV 'International Linear Collider' (ILC), based on superconducting 1.3 GHz RF technology; the multi-TeV 'Compact Linear Collider' (CLIC) is based on a novel technology of 12 GHz RF by a driver beam. Two detector concepts for ILC have been validated: the 'International Large Detector' (ILD), with a TPC plus silicon tracker; and the 'Silicon Detector' (SiD), based on all-silicon tracking; both concepts make use of particle flow calorimetry. The CLIC detector study is based on modified versions of both ILD and SiD. Next milestones are a Conceptual Design Report for CLIC (2011), and Technical Design Reports for ILC and its detectors (2012). However, a decision for realizing either ILC or CLIC must wait until LHC has shown relevant results of 'new physics'. (author)