Team Members: Courtney Linn, Austin Goe
A muon is an elementary particle such as the electron, a particle believed to not have any substructure. Courtney Linn and Austin Goe set out to calculate the lifetime of this particle through scintillation coincidence detectors. A scintillator is a material that luminesces when it interacts with ionizing radiation, such as muon decay.
The primary goal of the experiment is to measure the relative abundance of plus and minus muons. This is achieved when the minus muon is catapulted around the hydrogen comprising the scintillator, thus giving the minus muon a slightly longer effective lifetime. The photons from the scintillator then cause an electric pulse which is viewed by a photomultiplier tube which the team records. A pulse can be seen when a muon initially enters the detector. As the muon decays into a neutrino another weaker pulse can be seen, allowing the team to determine the lifetime of a muon. Goe and Linn hoped to see a spread of polarity of the muons created in the lifetime variations of the particles.
Muons originate as a cosmic ray proton that strikes an atomic nuclei in the upper atmosphere. When the cosmic ray strikes, pions are created which decay into muons and neutrinos. The muons from the cosmic rays tend to travel in the same direction as the pion it originated from at near the speed of light. The muons that eventually reach the surface, due to relativity, vary in their point in life. Though muons are not believed to have a substructure, they do decay into other elementary particles via the weak nuclear force.
The detection of muons for the project was not as expected. To gather more accurate data, the team put detectors in series, consequently slowing down the sampling rate. The sampling rate of the detectors were not high enough to support the project within the amount of time available. To obtain the amount of data needed, the detectors would have to run past graduation. Despite not being able to obtain their goal, the team is anxious to learn of the results as the experiment runs over the summer.