CLAS detector

rdf:langString CLAS detector

rdf:langString CEBAF Large Acceptance Spectrometer (CLAS) is a nuclear and particle physics detector located in the experimental Hall B at Jefferson Laboratory in Newport News, Virginia, United States. It is used to study the properties of the nuclear matter by the collaboration of over 200 physicists (CLAS Collaboration) from many countries all around the world. The 0.5 to 12.0 GeV electron beam from the accelerator of Jefferson Laboratory is brought into "Hall B", the experimental hall that houses the CLAS system. Electrons or photons in the incoming beam collide with the nuclei of atoms in the physics "target" located at the center of CLAS. These collisions generally produce new particles, often after the target nucleons (protons and neutrons) are briefly excited to heavier-mass versions of the familiar protons and neutrons. A whole variety of intermediate-mass short-lived particles called "mesons" can be created. Scattered electron as well as the longer-lived produced particles travel through the CLAS detector, where they are measured. Particle physicists use these measurements to deduce the underlying structure of protons and neutrons and to better understand the interactions that create these new particles. The CLAS detector system was operational from 1998 until May 2012. From that time onward, analysis of archived data continued for some years, as can be traced in the publications. Since 2012, a similar but new system called CLAS12 was constructed, which began operations with particle beams in 2017.