Exotics — Same Blocks, New Combinations
Protons and neutrons — of which almost all things are made — are familiar
examples of three-quark particles. But if our understanding of the strong force is correct,
nature must also combine quarks and gluons into many particles of a completely new, exotic
type. Why? Because the strong force binds to itself — glue attracts glue.
So far, experiments have provided only hints that these exotics exist.
New measurements are needed to prove their existence and study their
properties carefully. The proposed 12 GeV energy upgrade at Jefferson
Lab can make these measurements.
If we do not find these exotics, our picture of the strongest force in the universe must have
serious flaws. Significant changes to the theory of nature's building blocks will then be
needed.