Uncovering the single top: observation of electroweak top quark production
- Michigan State Univ., East Lansing, MI (United States)
The top quark is generally produced in quark and anti-quark pairs. However, the Standard Model also predicts the production of only one top quark which is mediated by the electroweak interaction, known as 'Single Top'. Single Top quark production is important because it provides a unique and direct way to measure the CKM matrix element Vtb, and can be used to explore physics possibilities beyond the Standard Model predictions. This dissertation presents the results of the observation of Single Top using 2.3 fb-1 of Data collected with the D0 detector at the Fermilab Tevatron collider. The analysis includes the Single Top muon+jets and electron+jets final states and employs Boosted Decision Tress as a method to separate the signal from the background. The resulting Single Top cross section measurement is: (1) σ(p$$\bar{p}$$→ tb + X, tqb + X) = 3.74-0.74+0.95 pb, where the errors include both statistical and systematic uncertainties. The probability to measure a cross section at this value or higher in the absence of signal is p = 1.9 x 10-6. This corresponds to a standard deviation Gaussian equivalence of 4.6. When combining this result with two other analysis methods, the resulting cross section measurement is: (2) σ(p$$\bar{p}$$ → tb + X, tqb + X) = 3.94 ± 0.88 pb, and the corresponding measurement significance is 5.0 standard deviations.
- Research Organization:
- Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- AC02-07CH11359
- OSTI ID:
- 965012
- Report Number(s):
- FERMILAB-THESIS-2009-31; TRN: US0903561
- Country of Publication:
- United States
- Language:
- English
Similar Records
Discovery of single top quark production
Top Quark Produced Through the Electroweak Force: Discovery Using the Matrix Element Analysis and Search for Heavy Gauge Bosons Using Boosted Decision Trees