Physics Commons^™

Measurement Of The Prompt Double J/Psi Production Cross Section In Pp Collisions At Sqrt(S) = 7 Tev, Andrew David York

Doctoral Dissertations

The simultaneous production of two J/psi mesons has been significantly observed in proton-proton collisions at a center-of-mass energy of 7 TeV with the CMS detector. The two J/psi mesons are fully reconstructed in their decay to muons. The signal yield is extracted with an extended maximum likelihood fit based on four event variables. A method was developed to correct for detector acceptances and efficiencies based on the measured momenta of the J/psi and their decay muons to maintain the least model dependence possible.

The measurement is performed in an acceptance region defined by the individual J/psi transverse momentum and rapidity. …

Ttbar Production Cross Section Measurement In The Muon Plus Jets Channel Using Soft Electron Tagging In Pp Collisions At Sqrt(S) = 8 Tev, Jason Keller

Department of Physics and Astronomy: Dissertations, Theses, and Student Research

A measurement is made of the top quark pair production cross section through the decay channel ttbar -> mu nu + jets, carried out using the Compact Muon Solenoid (CMS) detector at the Large Hadron Collider (LHC), located at CERN in Geneva, Switzerland. The top quark pair events were produced in proton-proton collisions at a center-of-mass energy of 8 TeV. To facilitate the detection of ttbar events, jets produced from bottom quarks, which are decay products of the top quarks, are identified using electrons with low transverse momentum with respect to the beam axis (soft electrons). The dominant background, W …