Blessed Results of Single Top analysis with 0.7 fb-1

Results of Single Top analysis with 0.7 fb^-1 of CDF II data

Sarah Budd^b, Matthias Bühler^c, Thorsten Chwalek^c, Catalin Ciobanu^b, Peter Dong^a,
Richard Hughes^d, Thomas Junk^b, Kevin Lannon^d, Jan Lück^c, Thomas Müller^c,
Svenja Richter^c, Jason Slaunwhite^d, Bernd Stelzer^a, Jeannine Wagner^c, Wolfgang Wagner^c

^aUniversity of California, Los Angeles
^bUniversity of Illinois, Urbana-Champaign
^cUniversität Karlsruhe
^dOhio State University, Columbus

E-mail list of authors

We report results from a search for single-top-quark production in a 0.7 fb^-1 dataset accumulated with the CDF II detector. We employ two different multivariate techniques to analyze the data, one using neural-networks discriminants and the other using a multivariate likelihood. Neither method finds a significant evidence of a signal, and 95% confidence level limits are set under various scenarios.

technique sigma (t + s-Channel) sigma (t-Channel) sigma (s-Channel)

neural networks
upper limits < 3.4 pb @ 95% C.L. < 3.1 pb @ 95% C.L. < 3.2 pb @ 95% C.L.

multivariate likelihood
upper limit < 4.3 pb @ 95% C.L. < 2.9 pb @ 95% C.L. < 5.1 pb @ 95% C.L.

neural networks
best fit 0.8 ^+1.3_-0.8 (stat.) ^+0.2_-0.3 (syst.) pb 0.6 ^+1.9_-0.6 (stat.) ^+0.1_-0.1 (syst.) pb 0.3 ^+2.2_-0.3 (stat.) ^+0.5_-0.3 (syst.) pb

Description of our analysis. (ps)

Our single top results were approved (blessed) by CDF on Thursday 03/16/2006.

General Results

Tables (1)
Event Yield:
EPS GIF
Systematics Rate Uncertainty (Abbr.):
EPS GIF
Systematics Rate Uncertainty (not Abbr.):
EPS GIF

Tables (2)
Systematics Shape Uncertainty (Abbr.):
EPS GIF
Systematics Shape Uncertainty (not Abbr.):
EPS GIF
Summary of Upper Limits:
EPS GIF

Neural Networks b-tagger:
W + 1jet
EPS GIF
W + 2jet
EPS GIF
W + 3jet
EPS GIF

Data Monte Carlo comparison:
Top Mass:
EPS GIF
Q*Eta:
EPS GIF
Ht:
EPS GIF

Data Monte Carlo comparison:
cos(Theta(q,l)):
EPS GIF

Neural Network Technique Results

Multivariate Likelihood Technique Results

Link to Results of Single Top Analysis with 162 pb^-1

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Results of Single Top analysis with 0.7 fb^-1 of CDF II data
Sarah Budd^b, Matthias Bühler^c, Thorsten Chwalek^c, Catalin Ciobanu^b, Peter Dong^a, Richard Hughes^d, Thomas Junk^b, Kevin Lannon^d, Jan Lück^c, Thomas Müller^c, Svenja Richter^c, Jason Slaunwhite^d, Bernd Stelzer^a, Jeannine Wagner^c, Wolfgang Wagner^c
^aUniversity of California, Los Angeles ^bUniversity of Illinois, Urbana-Champaign ^cUniversität Karlsruhe ^dOhio State University, Columbus
E-mail list of authors
We report results from a search for single-top-quark production in a 0.7 fb^-1 dataset accumulated with the CDF II detector. We employ two different multivariate techniques to analyze the data, one using neural-networks discriminants and the other using a multivariate likelihood. Neither method finds a significant evidence of a signal, and 95% confidence level limits are set under various scenarios.
technique	sigma (t + s-Channel)	sigma (t-Channel)	sigma (s-Channel)
neural networks upper limits	< 3.4 pb @ 95% C.L.	< 3.1 pb @ 95% C.L.	< 3.2 pb @ 95% C.L.
multivariate likelihood upper limit	< 4.3 pb @ 95% C.L.	< 2.9 pb @ 95% C.L.	< 5.1 pb @ 95% C.L.
neural networks best fit	0.8 ^+1.3_-0.8 (stat.) ^+0.2_-0.3 (syst.) pb	0.6 ^+1.9_-0.6 (stat.) ^+0.1_-0.1 (syst.) pb	0.3 ^+2.2_-0.3 (stat.) ^+0.5_-0.3 (syst.) pb
Description of our analysis. (ps)
Our single top results were approved (blessed) by CDF on Thursday 03/16/2006.

Last modified: Wed Apr 19 15:25:34 CEST 2006 by Matthias Bühler (mbuehler @ fnal.gov)

General Results
Tables (1)	Event Yield: EPS GIF	Systematics Rate Uncertainty (Abbr.): EPS GIF	Systematics Rate Uncertainty (not Abbr.): EPS GIF
Tables (2)	Systematics Shape Uncertainty (Abbr.): EPS GIF	Systematics Shape Uncertainty (not Abbr.): EPS GIF	Summary of Upper Limits: EPS GIF
Neural Networks b-tagger:	W + 1jet EPS GIF	W + 2jet EPS GIF	W + 3jet EPS GIF
Data Monte Carlo comparison:	Top Mass: EPS GIF	Q*Eta: EPS GIF	Ht: EPS GIF
Data Monte Carlo comparison:	cos(Theta(q,l)): EPS GIF