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Title: Search for vector-like quark production in the lepton+jets and dilepton+jets final states using 5.4 fb-1 of Run II data

Thesis/Dissertation ·
DOI:https://doi.org/10.2172/1002005· OSTI ID:1002005
 [1]
  1. Columbia Univ., New York, NY (United States)

The Standard Model of particle physics provides an excellent description of particle interactions at energies up to ~1 TeV, but it is expected to fail above that scale. Multiple models developed to describe phenomena above the TeV scale predict the existence of very massive, vector-like quarks. A search for single electroweak production of such particles in p$$\bar{p}$$ collisions at a center-of-mass energy of 1.96 TeV is performed in the W+jets and Z+jets channels. The data were collected by the DØ detector at the Fermilab Tevatron Collider and correspond to an integrated luminosity of 5.4 fb-1. Events consistent with a heavy object decaying to a vector boson and a jet are selected. We observe no significant excess in comparison to the background prediction and set 95% confidence level upper limits on production cross sections for vector-like quarks decaying to W+jet and Z+jet. Assuming a vector-like quark -- standard model quark coupling parameter $$\tilde{κ}$$qQ of unity, we exclude vector-like quarks with mass below 693 GeV for decays to W+jet and mass below 449 GeV for decays to Z+jet. These represent the most sensitive limits to date.

Research Organization:
Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
Sponsoring Organization:
USDOE
DOE Contract Number:
AC02-07CH11359
OSTI ID:
1002005
Report Number(s):
FERMILAB-THESIS-2010-56; TRN: US1100812
Country of Publication:
United States
Language:
English