UCLA

In 2011 and 2012, the Compact Muon Solenoid (CMS) experiment at the Large Hadron Collider (LHC) collected 19.7 fb−1 of data at a center of mass energy of √s = 8 TeV. During the time period immediately following, called the Long Shutdown 1, the LHC was turned off to allow for the upgrade of the hardware of the experiments and the collider for a restart at √s = 13 TeV. This thesis focuses on two topics. The first is the construction and testing of new Cathode Strip Chambers which were installed in the Compact Muon Solenoid. The second is a measurement of the cross sections of the Z/γ∗ + jets and γ + jets processes, where the Z decays to either an electron-positron pair (e+e−) or a muon pair (μ+μ−), the ratio of the cross sections of the Z/γ∗ + jets process to the γ + jets process, and the shapes of the Z/γ∗ + jets events, namely the azimuthal angle φ between the Z boson and the three leading jets. These distributions are compared to the predictions of two leading order MC generators, MadGraph and Sherpa, which are well-tested MC generators. The distributions are also compared to a relatively new next-to-leading-order MC generator, BlackHat, which was untested against CMS data.