Forward-Backward Asymmetry of Top Quark Pair Productionn at the Fermilab Tevatron

Thesis/Dissertation · Tue Dec 01 00:00:00 EST 2015

DOI:https://doi.org/10.2172/1248218· OSTI ID:1248218

Hong, Ziqing ^[1]

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1. Texas A & M Univ., College Station, TX (United States)

This dissertation presents the final measurements of the forward-backward asymmetry (A_FB) of top quark-antiquark pair events (t t^-) at the Collider Detector at Fermilab (CDF) experiment. The t t^- events are produced in proton{anti-proton collisions with a center of mass energy of 1:96 TeV during the Run II of the Fermilab Tevatron. The measurements are performed with the full CDF Run II data (9.1 fb^-1) in the final state that contain two charged leptons (electrons or muons, the dilepton final state), and are designed to con rm or deny the evidence-level excess in the AFB measurements in the final state with a single lepton and hadronic jets (lepton+jets final state) as well as the excess in the preliminary measurements in the dilepton final state with the first half of the CDF Run II data. New measurements include the leptonic AFB (A^l_FB), the lepton-pair A_FB (A^ll _FB) and the reconstructed top AFB (At t _FB). Each are combined with the previous results from the lepton+jets final state measured at the CDF experiment. The inclusive A^l _FB, A^ll _FB, and At t _FB measured in the dilepton final state are 0.072 ± 0.060, 0.076 ± 0.081, and 0.12 ± 0.13, to be compared with the Standard Model (SM) predictions of 0.038 ± 0.003, 0.048 ± 0.004, and 0.010 ± 0.006, respectively. The CDF combination of A^l_FB and At t _FB are 0.090^+0:028 _-0.026, and 0.160 ± 0.045, respectively. The overall results are consistent with the SM predictions.

• Research Organization: Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
• Sponsoring Organization: USDOE Office of Science (SC), High Energy Physics (HEP)
• DOE Contract Number: AC02-07CH11359
• OSTI ID: 1248218
• Report Number(s): FERMILAB-THESIS-2015-30; 1410010
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS