The CLAS12 Spectrometer in Hall B at Jefferson Laboratory

摘要

Quantum Chromodynamics (QCD) is the theory of strong interactions between quarks and gluons, the fundamental particles that make up composite hadrons such as protons, neutrons, and pions. The laws of QCD are elegant and concise, however, applying them in experimental processes to unravel the structural complexity of hadrons in terms of their fundamental constituents remains one of the most challenging problems in hadronic and nuclear physics today. This challenge motivates the newest generation of facilities and experiments. In the period from 1997 to 2012 the CEBAF Large Acceptance Spectrometer (CLAS) in Hall B at Jefferson Laboratory was used for studies of inclusive, semi-inclusive, and exclusive reactions from a fixed target with beams of electrons and photons at energies up to 6 GeV. CLAS completed the first generation of experiments with tremendous achievements in the field of hadronic physics. CLAS delivered on its initial science program, pioneered new measurements, and opened up new directions in our field. These successes of the past decades have posed and sharpened questions that are central to our understanding of QCD that are now within the reach of the Jefferson Lab 12 GeV energy upgrade.