Bridging Two Ways of Understanding Nuclei

In the traditional view, the atom's nucleus appears as a cluster of nucleons-protons and neutrons. A deeper view reveals quarks and gluons inside the nucleons. CEBAF's continuous, energetic beams of probing electrons let physicists examine how the two views fit together. Ultimately, the process of

The accelerator complex at Jefferson Lab. In the three circular, grass-domed experimental halls (right foreground), beams of electrons form the underground, racetrack-shaped CEBAF accelerator probe deeply inside atoms. The research, begun in the mid- 1990s, generates new fundamental knowledge about the nucleus at the atom's core - and therefore about matter itself.

bridging the views will yield a complete understanding of nuclear matter - 99.5% of everything around us. We will know more clearly how matter itself is put together, and how it gets its characteristic properties.

The initial years of research at Jefferson Lab have started the bridging process. Some experiments have tested predictions about nucleon structure from QCD, the mathematically expressed quantum chromodynamics theory that guides physicists' thinking about the subnuclear realm. Other high-precision experiments have scrutinized few-nucleon systems in unprecedented detail. New knowledge has begun to emerge in the form of scientific papers in the world's leading physics journals.

No one can foretell the practical results to come years or decades from now. But history shows a clear pattern: fundamental knowledge about matter itself has led to useful technologies, from medical X-rays and MRIs to transistors and integrated circuits for TVs and computers.

Experimental Hall A Experimental Hall C

Experimental Hall B

Inside the halls, incoming electrons or photons - particles of light generated by the electrons - interact with nuclei in experimental targets. State-of-the-art particle-detection and data-acquisition equipment enables experiments to gather and sort immense amounts of useful data.

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