Measurement of the Top Quark Mass

Thesis/Dissertation · Tue Apr 01 04:00:00 EST 1997

DOI:https://doi.org/10.2172/1421735· OSTI ID:1421735

Varnes, Erich Ward ^[1]

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1. LBL, Berkeley

This dissertation describes the measurement of the top quark mass mt using events recorded during a 125 $$pb^{-1}$$ exposure of the D0 detector to $$\sqrt{s}$$ = 1.8 TeV $$\bar{p}p$$ collisions. Six events consistent with the hypothesis $$t\bar{t} \to bW^+ \bar{b}W^- \to b\bar{\ell} \nu, \bar{b}\ell \bar{\nu}$$ form the dilepton sample. The kinematics of such events may be reconstructed for any assumed mt, and the likelihood of each such solution evaluated. A measurement of $$m_t$$ based on these relative solution likelihoods gives $$m_t$$ = 169.9 $$\pm$$ 14.8 (stat.) $$\pm$$ 3.8 (syst.) GeV/$c^2$. A 2C kinematic fit is performed on a sample of 77 events consistent with $$t\bar{t} \to bW^+ \bar{b}W^- \to b\bar{\ell}\nu, \bar{b}q\bar{q}$$ and this, in combination with an estimate on the likelihood that each event is top, yields $$m_t$$ = 173.3 $$\pm$$ 5.6 (stat.) $$\pm$$ 6.2 (syst.) GeV/$c^2$. A combination of these two measurements gives $$m_t$$ = 173.1 $$\pm$$ 5:2 (stat.) $$\pm$$ 5.7 (syst.) GeV/$c^2$.

• Research Organization: Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States); 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: 1421735
• Report Number(s): FERMILAB-THESIS-1997-28; UMI-98-03383; LBL-40283; LBNL-40283; 444599
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS