JV-Event+Identification

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Here are six types of events in particle physics: Z- q+q- (two jets): The picture above displays a two jet quark. The two jets are represented by the two different colors (in this case red and green). This can also be identified as a two quark jet by the “spray” (the curved lines in red and green). Although they are very similar to tau decays they are different in not only the spray but also the energy level.

Z- q+q- (three jets): This event is similar to the other quark jet decays. The only difference is the addition of a third color, blue.



Z- q+q- (four jets): This event is pretty much similar to the two and three jet quark decay. The only difference is the addition of a fourth color, yellow.



Z-µ+µ-: This image is a muon decay signature. Muons are typically clean (not a lot of spray) but the interesting thing about muon decays is that they typically have very high energy. At the beginning the Z boson’s energy is at 91GeV. In this image the final energy measurement is 105.3 GeV which much higher than the original.



The picture above displays Z-to-tau decay. A Tau look similar to quarks but there are some subtle differences. First a tau is usually a lot “cleaner” than quarks. What is meant by “cleaner” is that there is less spray in the image. The other difference is that a tau typically has extremely low energy. The low energy is an example of conservation of energy. Because of the low energy in the tau it must be assumed that there is a huge amount of neutrinos present and that is where the rest of the energy went.



Z-e+e-: The image above displays a Z-to-electron decay. Electron decay signatures are clean single track events that don’t make it past the ECal (Electron Calorimeter). There are also signs of energy outside of ECal. The box shapes that are depicted in green and red are representations of energy.