Number 318 (Story #3), April 23, 1997 by Phillip F. Schewe and Ben Stein
FIRST RESULTS FROM JEFFERSON LAB. This new nuclear physics facility in Newport News, Virginia explores the interface between the physics of the nucleus (made of protons and neutrons) and the physics of individual protons and neutrons (made of quarks held together by particles known as gluons). The main machine at Jefferson Lab is the Continuous Electron Beam Accelerator Facility (CEBAF), which accelerates continuous streams of electrons to energies of 4 GeV (with a maximum energy of 8 GeV planned for the future); the electrons are then diverted to one of three experimental halls where they collide with fixed targets containing nuclei. At the APS meeting Rolf Ent of Jefferson Lab described how electron collisions with nuclei are ejecting protons from nuclei at a greater rate than anticipated by the present theories on the subject. Exploring how gamma rays break up deuterons (containing a proton and neutron), Haiyan Gao of Argonne presented measurements showing that the quark substructure inside the deuteron must be taken into account to properly understand the breakup process.(CEBAF illustration at Physics News Graphics)
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