First Measurement of Top Quark Pair Production Cross-Section in Muon Plus Hadronic Tau Final States

• Other Authors: Sumowidagdo, Suharyo (authoraut)
• Format: Others
• Language: English; English
• Published: Florida State University
• Subjects: Physics
• Online Access: http://purl.flvc.org/fsu/fd/FSU_migr_etd-0407

This dissertation presents the first measurement of top quark pair production cross-section in events containing a muon and a tau lepton. The measurement was done with 1 fb−1 of data collected during April 2002 through February 2006 using the DØ detector at the Tevatron proton-antiproton collider, located at Fermi National Accelerator Laboratory (Fermilab), Batavia, Illinois. Events containing one isolated muon, one tau which decays hadronically, missing transverse energy, and two or more jets (at least one of which must be tagged as a heavy flavor jet) were selected.Twenty-nine candidate events were observed with an expected background of 9.16 events. The top quark pair production cross-section is measured to beσ (t¯t) = 8.0+2.8 −2.4 (stat)+1.8−1.7 (syst) ± 0.5 (lumi) pb.Assuming a top quark pair production cross-section of 6.77 pb for Monte Carlo signal top events without a real tau, the measured σ × BR isσ (t¯t) × BR(t¯t μ +τ + 2ν + 2b) = 0.18+0.13−0.11 (stat)+0.09−0.09 (syst) ± 0.01 (lumi) pb. === A Dissertation submitted to the Department of Physics in partial fulfillment of the requirements for the degree of Doctor of Philosophy. === Degree Awarded: Spring Semester, 2008. === Date of Defense: November 26, 2007. === Cross-section, D0, Tevatron, Fermilab, Tau lepton, Top quark === Includes bibliographical references. === Todd Adams, Professor Directing Dissertation; Ettore Aldrovandi, Outside Committee Member; Horst Wahl, Committee Member; Laura Reina, Committee Member; Simon Capstick, Committee Member.