Nucleons are the protons and neutrons of an atom. Courant's experiment involves witnessing the rarely observed breakdown of nucleons into their component particles. The project began with the construction of a 1,000-ton particle detector located 2,300 feet underground. Courant and other members of the University's Experimental High Energy Group built it to reduce interference from the millions of subatomic particles that constantly bombard the Earth's surface. In the three and a half years that the detector has operated, the scientists have found some promising examples of nucleon decay but nothing definite.
Neutrinos are neutral electron-like particles that originate from the sun or cosmic rays in space.
The neutrinos rain down on the Earth constantly, penetrating and passing through everything, Courant said. The 500 mile trip takes .001 seconds and requires the accelerator to aim the beam two degrees down to account for the curvature of the Earth. The new 10,000-ton detector is designed to observe the changes the neutrinos go through during the trip, when it is complete in 2001. The neutrino project is part of a large international collaboration of more than 80 physicists from the United States, United Kingdom, Russia and China. Ten University faculty members, from both physics and mechanical engineering, are also involved.