skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Measurement of the top - anti-top Production Cross Section at √s = 1.96-TeV in the e + jets Final State of proton anti-proton Collisions at the Tevatron

Abstract

We discuss the measurement of the cross section for t$$\bar{t}$$ production in p$$\bar{p}$$ collisions at √s = 1.96 TeV in e+jets final states observed at the D0 experiment at the Fermilab Tevatron. Our result is based on data collected from the June 2002 to September 2003 period of Run II of the p$$\bar{p}$$ Collider. In the Standard Model, the top quark is expected to decay mainly into a W boson and a b quark. The W boson can decay subsequently into a lepton and its neutrino or a q$$\bar{q}$$ quark-antiquark pair. In this thesis, we focus on the e + v e or e - $$\bar{v}$$ e decays of one of the W bosons and the q$$\bar{q}$$ decays of the other W boson in t$$\bar{t}$$ final states. The b, q and q' quarks appear as jets of particles in the detector, thereby defining the e+jets final state. We present two methods used for performing this measurement. The first method is based on a Random Grid Search (RGS) that minimizes the uncertainty on the extracted cross section. The variables used in the search take advantage of differences between expected background and signal processes to obtain the yield of t$$\bar{t}$$ events. Themore » second method uses a Neural Network (NN) procedure that discriminates signal from background through the application of a NN trained on simulated t$$\bar{t}$$ signal and W+jets background events. The preliminary results presented in this thesis for inclusive t$$\bar{t}$$ production are σ p$$\bar{p}$$ → t$$\bar{t}$$ + x of 7.9$$+2.6\atop{-2.4}$$(stat) $$+2.2\atop{-2.3}$$(syst) ± 0.5 (L) pb for the NN analysis, where the uncertainties correspond to contributions from statistical and systematic sources and from the uncertainty on luminosity. Our measurements are consistent with each other, and are within error of the value of 6.77 ± 0.42 pb expected in the Standard Model.« less

Authors:
 [1]
  1. Univ. of Rochester, NY (United States)
Publication Date:
Research Org.:
Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
879153
Report Number(s):
FERMILAB-THESIS-2005-31
TRN: US0605020
DOE Contract Number:  
AC02-76CH03000
Resource Type:
Thesis/Dissertation
Country of Publication:
United States
Language:
English
Subject:
43 PARTICLE ACCELERATORS; 72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; B QUARKS; CROSS SECTIONS; DECAY; FERMILAB TEVATRON; INTERMEDIATE BOSONS; LEPTONS; LUMINOSITY; NEURAL NETWORKS; NEUTRINOS; PRODUCTION; PROTONS; QUARKS; STANDARD MODEL; T QUARKS; Experiment-HEP

Citation Formats

Cho, DooKee. Measurement of the top - anti-top Production Cross Section at √s = 1.96-TeV in the e + jets Final State of proton anti-proton Collisions at the Tevatron. United States: N. p., 2005. Web. doi:10.2172/879153.
Cho, DooKee. Measurement of the top - anti-top Production Cross Section at √s = 1.96-TeV in the e + jets Final State of proton anti-proton Collisions at the Tevatron. United States. https://doi.org/10.2172/879153
Cho, DooKee. Sat . "Measurement of the top - anti-top Production Cross Section at √s = 1.96-TeV in the e + jets Final State of proton anti-proton Collisions at the Tevatron". United States. https://doi.org/10.2172/879153. https://www.osti.gov/servlets/purl/879153.
@article{osti_879153,
title = {Measurement of the top - anti-top Production Cross Section at √s = 1.96-TeV in the e + jets Final State of proton anti-proton Collisions at the Tevatron},
author = {Cho, DooKee},
abstractNote = {We discuss the measurement of the cross section for t$\bar{t}$ production in p$\bar{p}$ collisions at √s = 1.96 TeV in e+jets final states observed at the D0 experiment at the Fermilab Tevatron. Our result is based on data collected from the June 2002 to September 2003 period of Run II of the p$\bar{p}$ Collider. In the Standard Model, the top quark is expected to decay mainly into a W boson and a b quark. The W boson can decay subsequently into a lepton and its neutrino or a q$\bar{q}$ quark-antiquark pair. In this thesis, we focus on the e+ ve or e- $\bar{v}$e decays of one of the W bosons and the q$\bar{q}$ decays of the other W boson in t$\bar{t}$ final states. The b, q and q' quarks appear as jets of particles in the detector, thereby defining the e+jets final state. We present two methods used for performing this measurement. The first method is based on a Random Grid Search (RGS) that minimizes the uncertainty on the extracted cross section. The variables used in the search take advantage of differences between expected background and signal processes to obtain the yield of t$\bar{t}$ events. The second method uses a Neural Network (NN) procedure that discriminates signal from background through the application of a NN trained on simulated t$\bar{t}$ signal and W+jets background events. The preliminary results presented in this thesis for inclusive t$\bar{t}$ production are σ p$\bar{p}$ → t$\bar{t}$ + x of 7.9$+2.6\atop{-2.4}$(stat) $+2.2\atop{-2.3}$(syst) ± 0.5 (L) pb for the NN analysis, where the uncertainties correspond to contributions from statistical and systematic sources and from the uncertainty on luminosity. Our measurements are consistent with each other, and are within error of the value of 6.77 ± 0.42 pb expected in the Standard Model.},
doi = {10.2172/879153},
url = {https://www.osti.gov/biblio/879153}, journal = {},
number = ,
volume = ,
place = {United States},
year = {2005},
month = {1}
}

Thesis/Dissertation:
Other availability
Please see Document Availability for additional information on obtaining the full-text document. Library patrons may search WorldCat to identify libraries that hold this thesis or dissertation.

Save / Share: