Observation of Top Quark Pair Production in the Dilepton Decay Channel from $$p\bar{p}$$ Collisions at 1.8-TeV

Thesis/Dissertation · Mon Jan 01 04:00:00 EST 1996

DOI:https://doi.org/10.2172/1422804· OSTI ID:1422804

Kruse, Mark Charles ^[1]

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1. Purdue U.

This thesis presents the results of a search for the top quark using data obtained at the Collider Detector at Fermilab (CDF) in $$p\bar{p}$$ collisions at a center-of-mass energy of $$\sqrt{s}$$ = 1:8TeV . The data represents an integrated luminosity of 109 $$pb^{-1}$$. The search includes the Standard Model tt decays with final states in the dilepton channel; $$t\bar{t} \to \ell^+ \nu_{\ell}b \ell^- \bar{\nu}_{\ell} \bar{b}$$, where $$\ell$$ = e or $$\mu$$. Such events are characterized by 2 high momentum leptons, 2 $$b$$ quark jets, and missing energy from the undetected neutrinos. Nine events were observed to pass the selection based on these characteristics, with an estimated background of 2.1 $$\pm$$ 0.4 events. The probability for an upward uctuation of the background to produce the observed signal is 6.3 x $$10^{-4}$$, which corresponds to an excess of 3.2$$\sigma$$. The excess is identified as $$t\bar{t}$$ production, and gives a measured cross-section of $$\sigma_{t \bar{t}} = 8.2 ^{+4.3}_{-3.3} pb$$.

• Research Organization: Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States)
• Sponsoring Organization: USDOE Office of Science (SC), High Energy Physics (HEP) (SC-25)
• DOE Contract Number: AC02-07CH11359
• OSTI ID: 1422804
• Report Number(s): FERMILAB-THESIS-1996-15; UMI-96-38193; 429129
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS