The University of Sofia “St. Kliment Ohridski” has been established in 1888 and it’s the oldest and the biggest university in Bulgaria. The nuclear and particle physics researches are conducted in the Faculty of Physics and covered several research fields: particle physics, nuclear physics, radioecology, natural radioactivity and metrology of ionizing radiation, simulation of physical processes, etc. The University offers Bachelor and Master program in Nuclear and Particle Physics. The BSc program is thought wholly in English language, while MSc is tought wholly in Bulgarian or in English depending of the student preferences. The Faculty offers also a PhD program in Nuclear and Particle Physics.

The high quality of the research and the education is ensured by several laboratories: Particle Physics Laboratory, GRID Technology Laboratory, Experimental Nuclear Physics Laboratory, Nuclear Electronics Laboratory, Laboratory for Computer Simulations of Physical Processes, Dosimetry and Radiation Protection Laboratory, Biophysics Laboratory and various other laboratories. Scientists from the Univeristy participate in numerous particle physics experiments: HYPERON, CHORUS, HARP, NA61, NA48, NA49, NA62, CMS, SHIP, ISOLDE, JEM-EUSO, PADME, MICE, EUROnu/IDS-NF. Many of the experiments are carried out at JINR-Dubna or at CERN. Scientist from the Faculty perform also theoretical research in the field of Mathematica Physics and QFT.

A group of researchers from the Faculty of Physics has joined the CMS from the very beginning. The group main contributions are in the design of the CMS HCAL system and in the production, installation and commissioning of the CMS RPC system. The team continues to contribute to a various aspects of the CMS Muon system, data taking and physical analysis. The University of Sofia has GRID Tier-3 centre and also contribute to the CMS computing.