What Happens When Things Go Very Fast?

Information about Experiment E687

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The image of the elephant at right is to scale with the detector sketch.

In this experiment, a high-energy photon strikes a stationary chunk of beryllium. This collision occasionally results in the creation of a charmed meson. Charmed mesons do not live very long before they decay into two other particles, a pion and a kaon.

Events are mapped by detectors which gather information for each particle. Calorimeters, which determine the energy of the particles and the physical location of the events, are spread throughout the experiment. A magnet system determines the momentum and charge of the particles.

Scientists measure charge, energy and momentum for the multitude of particles. Measurements on decay particles yield information regarding the original particle.

Check the Glossary for terms with which you are unfamiliar.