Week+of+9-17+to+9-23

September 19th
Today I arrived at 4:00 and John started Jeremiah and I into our project of finding cosmic rays. Cosmic rays are particles that came from space. They interfere with experiments in the LHC and the CMS detector because they are so small and fast and are not intended as parts of the experiments, but the experiments in the CMS detector are on a small enough scale that the cosmic rays have a significant effect on our data. The LHC was built underground in order to try to prevent things such as cosmic rays from interfering with experiments, but in order to get the materials underground to assemble the LHC, a hole had to be dug, so at least some cosmic rays were able to enter the underground space where the LHC is. Our project is going to be to look through data from CMS detector experiments and find where the cosmic rays are in the data. John showed us a spreadsheet of CMS data and explained what some of the columns mean. Some things were self-evident, such as energy and the momentum in certain directions, but something new I learned was the way the angles are measured for the particles that come out of a collision. Two angle measurements are used: phi and eta. Phi is used for the measurement of the angle on the x-y plane, and is measured counterclockwise starting from the directly right position, similarly to measurements on the unit circle. Phi is measured in radian increments between the extremes of pi and negative pi. Eta is the measurement of the angle on the z plane, starting from the vertical position. Eta does not use radians or degrees, but rather the two extremes for eta are 1 and -1. Two other new concepts John taught us were the ideas of w and z particles. Due to conservation of momentum, two particles with mirrored momentum in relation to the original have to be created in a collision or else there would be an imbalance. Z particles are particles that break up into two electrons or two muons of opposite charge. W particles are trickier. They break up into one electron or one muon and then something like a neutrino that we cannot see. So, a collision with a w particle might appear to only create one particle, but if we look closer at the data we can find evidence of something we could not detect that keeps the conservation of momentum. The last thing I did today was reorganize my logbook. Going forward my main page will be an archive of links to weekly posts with links to special posts intermingled in the list. My current main page is shown below. Today was a flurry of new information and I learned a lot of interesting new things. It is almost 6:00 now and it is time for me to leave. After a productive day today, I am excited for all of the new, interesting learning opportunities the rest of the project holds.