Extreme densities
The Compressed Baryonic Matter (CBM) experiment will be one of the main scientific pillars of the future Facility for Antiproton and Ion Research (FAIR) in Darmstadt.
The goal of the CBM research program is to explore the QCD phase diagram in the region of high baryon densities using high-energy nucleus-nucleus collisions. This includes the study of the equation of state of nuclear matter densities as found in neutron stars. At the same time, there are programs to search for phase transitions, restoration of chiral symmetry, and exotic forms of (strange) nuclear matter.
The CBM detector is designed to measure the collective behavior of hadrons, along with rare probes such as multi-strange hyperons, charmed particles, and vector mesons decaying into lepton pairs, with unprecedented precision and statistics. These measurements provide a diagnosis of the nucleus-nucleus collision in a near-diagnostic manner.
Most of these particles will be studied for the first time in the FAIR energy range. To achieve the required precision, the measurements will be performed at reaction rates up to 10 MHz. This corresponds to 10 million collisions per second! Such an experiment requires very fast and radiation-hard detectors, a novel data readout and analysis concept, and a high-performance computer cluster for continuous analysis already during the experiment.
Several of the CBM detector systems, the data readout chain, and the event reconstruction system are being commissioned and are already being used in experiments during FAIR Phase 0. The unique combination of an accelerator delivering a high-intensity heavy ion beam with a modern high-rate experiment based on innovative detector and computer technology provides optimal conditions for a research program with significant discovery potential for fundamental properties of QCD matter.