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Title: Search for single top quark production in pbar p collisions at sqrt{s}=1.96 TeV in the missing transverse energy plus jets topology

Abstract

We report a search for single top quark production with the CDF II detector using 2.1 fb{sup -1} of integrated luminosity of p{bar p} collisions at {radical}s = 1.96 TeV. The data selected consist of events characterized by large energy imbalance in the transverse plane and hadronic jets, and no identified electrons and muons, so the sample is enriched in W {yields} {tau}{nu} decays. In order to suppress backgrounds, additional kinematic and topological requirements are imposed through a neural network, and at least one of the jets must be identified as a b quark jet. We measure an excess of signal-like events in agreement with the standard model prediction, but inconsistent with a model without single top quark production by 2.1 standard deviations ({sigma}), with a median expected sensitivity of 1.4 {sigma}. Assuming a top quark mass of 175 GeV/c{sup 2} and ascribing the excess to single top quark production, the cross section is measured to be 4.9{sub -2.2}{sup +2.5} (stat+syst) pb, consistent with measurements performed in independent datasets and with the standard model prediction.

Authors:
; ; ; ; ; ; ; ; ; ;
Publication Date:
Research Org.:
Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
971384
Report Number(s):
FERMILAB-PUB-10-018-E
Journal ID: ISSN 1550--7998; arXiv eprint number arXiv:1001.4577; TRN: US1001179
DOE Contract Number:  
AC02-07CH11359
Resource Type:
Journal Article
Journal Name:
Submitted to Phys.Rev.D
Additional Journal Information:
Journal Volume: 81; Journal Issue: 7; Journal ID: ISSN 1550--7998
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; B QUARKS; CROSS SECTIONS; ELECTRONS; FERMILAB COLLIDER DETECTOR; FORECASTING; LUMINOSITY; MUONS; NEURAL NETWORKS; PRODUCTION; SENSITIVITY; STANDARD MODEL; T QUARKS; TOPOLOGY; TRANSVERSE ENERGY; Experiment-HEP

Citation Formats

Aaltonen, T, /Helsinki Inst. of Phys., Adelman, J, /Chicago U., EFI, Alvarez Gonzalez, B, /Cantabria Inst. of Phys., Amerio, S, /INFN, Padua, Amidei, D, /Michigan U., Anastassov, A, /Northwestern U., Annovi, A, /Frascati, Antos, J, /Comenius U., Apollinari, G, /Fermilab, Appel, J, /Fermilab, Apresyan, A, and /Purdue U. /Waseda U. Search for single top quark production in pbar p collisions at sqrt{s}=1.96 TeV in the missing transverse energy plus jets topology. United States: N. p., 2010. Web. doi:10.1103/PhysRevD.81.072003.
Aaltonen, T, /Helsinki Inst. of Phys., Adelman, J, /Chicago U., EFI, Alvarez Gonzalez, B, /Cantabria Inst. of Phys., Amerio, S, /INFN, Padua, Amidei, D, /Michigan U., Anastassov, A, /Northwestern U., Annovi, A, /Frascati, Antos, J, /Comenius U., Apollinari, G, /Fermilab, Appel, J, /Fermilab, Apresyan, A, & /Purdue U. /Waseda U. Search for single top quark production in pbar p collisions at sqrt{s}=1.96 TeV in the missing transverse energy plus jets topology. United States. doi:10.1103/PhysRevD.81.072003.
Aaltonen, T, /Helsinki Inst. of Phys., Adelman, J, /Chicago U., EFI, Alvarez Gonzalez, B, /Cantabria Inst. of Phys., Amerio, S, /INFN, Padua, Amidei, D, /Michigan U., Anastassov, A, /Northwestern U., Annovi, A, /Frascati, Antos, J, /Comenius U., Apollinari, G, /Fermilab, Appel, J, /Fermilab, Apresyan, A, and /Purdue U. /Waseda U. Fri . "Search for single top quark production in pbar p collisions at sqrt{s}=1.96 TeV in the missing transverse energy plus jets topology". United States. doi:10.1103/PhysRevD.81.072003. https://www.osti.gov/servlets/purl/971384.
@article{osti_971384,
title = {Search for single top quark production in pbar p collisions at sqrt{s}=1.96 TeV in the missing transverse energy plus jets topology},
author = {Aaltonen, T and /Helsinki Inst. of Phys. and Adelman, J and /Chicago U., EFI and Alvarez Gonzalez, B and /Cantabria Inst. of Phys. and Amerio, S and /INFN, Padua and Amidei, D and /Michigan U. and Anastassov, A and /Northwestern U. and Annovi, A and /Frascati and Antos, J and /Comenius U. and Apollinari, G and /Fermilab and Appel, J and /Fermilab and Apresyan, A and /Purdue U. /Waseda U.},
abstractNote = {We report a search for single top quark production with the CDF II detector using 2.1 fb{sup -1} of integrated luminosity of p{bar p} collisions at {radical}s = 1.96 TeV. The data selected consist of events characterized by large energy imbalance in the transverse plane and hadronic jets, and no identified electrons and muons, so the sample is enriched in W {yields} {tau}{nu} decays. In order to suppress backgrounds, additional kinematic and topological requirements are imposed through a neural network, and at least one of the jets must be identified as a b quark jet. We measure an excess of signal-like events in agreement with the standard model prediction, but inconsistent with a model without single top quark production by 2.1 standard deviations ({sigma}), with a median expected sensitivity of 1.4 {sigma}. Assuming a top quark mass of 175 GeV/c{sup 2} and ascribing the excess to single top quark production, the cross section is measured to be 4.9{sub -2.2}{sup +2.5} (stat+syst) pb, consistent with measurements performed in independent datasets and with the standard model prediction.},
doi = {10.1103/PhysRevD.81.072003},
journal = {Submitted to Phys.Rev.D},
issn = {1550--7998},
number = 7,
volume = 81,
place = {United States},
year = {2010},
month = {1}
}