Observation of Single Top Quark Production and Measurement of |VtbV_{tb}| with CDF

Collaboration
Apr, 2010

Citations per year

20102014201820222025010203040
Abstract: (arXiv)
We report the observation of electroweak single top quark production in 3.2 fb-1 of ppbar collision data collected by the Collider Detector at Fermilab at sqrt{s}=1.96 TeV. Candidate events in the W+jets topology with a leptonically decaying W boson are classified as signal-like by four parallel analyses based on likelihood functions, matrix elements, neural networks, and boosted decision trees. These results are combined using a super discriminant analysis based on genetically evolved neural networks in order to improve the sensitivity. This combined result is further combined with that of a search for a single top quark signal in an orthogonal sample of events with missing transverse energy plus jets and no charged lepton. We observe a signal consistent with the standard model prediction but inconsistent with the background-only model by 5.0 standard deviations, with a median expected sensitivity in excess of 5.9 standard deviations. We measure a production cross section of 2.3+0.6-0.5(stat+sys) pb, extract the CKM matrix element value |Vtb|=0.91+0.11-0.11 (stat+sys)+-0.07(theory), and set a lower limit |Vtb|>0.71 at the 95% confidence level, assuming m_t=175 GeVc^2.
Note:
  • Submitted to Phys. Rev. D
  • 12.15.Ji
  • 12.15.Hh
  • 14.65.Ha
  • 13.85.Qk
  • OSG : CDF
  • anti-p p: interaction
  • truth: single production
  • transverse energy: missing-energy
  • final state: ((n)jet lepton)
  • final state: ((n)jet)