Background - Teaching Example - Assessment - Site Index
Modern particle physics experiments can only see some energetic particles indirectly. In other words, the particle physicists look for information that would signal a certain particle must have left behind.In this experiment the colliding accelerator beams have sufficient energy to create a Z boson. This particle is more than likely created at rest and quickly deacys into other particles that the detector can observe. This project gives students the information collected on these "daughter" particles so that the students can reconstruct the particle which must have decayed.
Students must apply the Laws of energy conservation and momentum conservation to recosntruct these unobserved particles. Since many pre-college students understand these laws this task is much easier than it sounds. The detector makes measurements that students can use to determine the energy and momentum of the observed partilces.
Once a student has accounted for all of the energy and momentum of detected particles she can then apply the conservation laws above to determine the momentum and energy of the "parent" particle. Knowing a particle's momentum and energy allows us to uniquely determine it's mass. Applying the conservation of charge to the observed particles allows one to determine the charge of the parent particle. These two descriptors allow for a fairly complete description of the unobserved particle.