Medium Energy

The Medium Energy subprogram primarily explores the low temperature frontier of quantum chromodynamics (QCD) to understand how the properties of existing matter arise from the properties of QCD. This research is conducted at two Nuclear Physics (NP) National User Facilities and other facilities worldwide. The Continuous Electron Beam Accelerator Facility (CEBAF) at the Thomas Jefferson National Accelerator Facility (TJNAF or JLab) provides high quality beams of polarized electrons that allow scientists to extract information on the quarks and gluons that make up protons and neutrons. CEBAF also uses polarized electrons to make precision measurements of processes that can provide information relevant to the intensity frontier to discover the New Standard Model. The Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory (BNL) provides colliding beams of spin-polarized protons to probe the spin structure of the proton, another important aspect of the QCD frontier. Experiments are also being carried out at Triangle Universities Nuclear Laboratory (TUNL) and Fermi National Accelerator Laboratory (FNAL or Fermilab). This subprogram also supports advanced detector R&D, instrumentation development as well as scientific research to exploit NP’s next new accelerator facility called the Electron-Ion Collider (EIC). The EIC will be a discovery machine for unlocking the secrets of the "glue" that binds the building blocks of visible matter in the universe.