The CERN Theory Group was founded in 1952, a couple of years before CERN was officially created in Copenhagen, under the guidance of Niels Bohr. It was then moved to Geneva together with the CERN experimental groups in 1957. In 2005, it was incorporated into the CERN Physics Department as the "Theory Unit". Since 2016 it once again became an independent department, the "Theoretical Physics Department".
Its main mandate is to:
- Be a center of excellence in theoretical high-energy physics and related areas, in all aspects.
- Provide support to the experimental program of CERN and profit from its stimulating environment.
- Be a high quality reference center for the international theoretical physics community in getting together, exchanging ideas and collaborating.
- Contribute to education, training and outreach onsite and elsewhere.
To this end, CERN-TH aims primarily to foster fundamental research in all fields of direct relevance for High Energy Physics, including cosmology, high-energy astrophysics, field and string theory. With the CERN-TH short-term visitor program, the series of CERN-TH Institutes, and a wide range of workshop activities, working groups and regular meetings, CERN-TH has flexible structures in place to facilitate the scientific exchange amongst theorists, and between theorists and experimentalists in the Laboratory and elsewhere. For the decisive coming years of LHC operation, these structures help to provide the worldwide HEP community with a forum that is well-suited for discussing the theoretical challenges of LHC data analysis and interpretation, for evaluating LHC results in a wider context including constraints from cosmology and astro-particle physics, and for coordinating contributions from theoretical High Energy Physics towards the formulation of concrete priorities for future experimental initiatives.
A particularly important contribution towards facilitating international collaboration and exchanging ideas are our "Theory Institutes", which are informal workshops lasting for up to a few weeks. They optimize our resources by bundling together visiting scientists with common interests, and sharing our resources with the international community.
Furthermore, members of CERN-TH are involved in the work of the Particle Data Group, as well as in several teaching activities, including the Academic Training, Summer Student and High-School Teacher programs, as well as in the European and Latin American and CERN-Fermilab Schools of High-Energy Physics. An important ongoing activity is the LHC Physics Centre at CERN (LPCC), which contributes with workshops, lectures and various working groups.
CERN-TH has a staff of about 24 people (typically 20 physicists and 3 secretaries and a computer scientist). In 2014, it published 270 preprints and hosted 59 fellows, 44 students, 37 scientific associates, 3 guest professors and 780 short-term visitors (482 paid), representing a total of 1,350 visitor weeks. CERN-TH organised 2 schools and 5 TH Institutes on site. It hosted 4 ERC grant holders (3 advanced and 1 consolidator), as well as one MCnet grant. The LHC Physics Centre at CERN organised a number of activities centred on the physics programme of the LHC and its upgrades, including 7 workshops and 32 working group meetings. It also organised 2 workshops and 14 WG meetings for the physics study of the FCC-hh project.
The two following references give some of the history of CERN-TH:
- Physics in the CERN Theory Division by John Iliopoulos, 1993
- Theoretical High Energy Physics: formal theory by Luis Alvarez-Gaume and Wolfgang Lerche, 2004
A comprehensive snapshot of current research activities in CERN-TH is given by the programme of the 2014 Theory Retreat.