Suche nach elektroschwacher Erzeugung einzelner Top-Quarks mit dem CDF-Experiment in Proton-Antiproton-Kollisionen bei 1,96 TEV Schwerpunktsenergie
Author: Thorsten Walter
Publisher:
Published: 2005
Total Pages: 157
ISBN-13:
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Search for Electroweak Single Top Quark Production with CDF in Proton Antiproton Collisions at S
Author: Thorsten Walter
Publisher:
Published: 2005
Total Pages: 157
ISBN-13:
DOWNLOAD EBOOKSearch for Electroweak Single Top Quark Production with Cdf in Proton - Anti-proton Collisions at S**(1/2)
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Published: 2006
Total Pages:
ISBN-13:
DOWNLOAD EBOOKAbstract Not Provided.
Search for Electroweak Single Top Quark Production with Cdf in Proton - Anti-proton Collisions at {u221A}s
Author:
Publisher:
Published: 2005
Total Pages: 157
ISBN-13:
DOWNLOAD EBOOKIn this thesis two searches for electroweak single top quark production with the CDF experiment have been presented, a cutbased search and an iterated discriminant analysis. Both searches find no significant evidence for electroweak single top production using a data set corresponding to an integrated luminosity of 162 pb-1 collected with CDF. Therefore limits on s- and t-channel single top production are determined using a likelihood technique. For the cutbased search a likelihood function based on lepton charge times pseudorapidity of the non-bottom jet was used if exactly one bottom jet was identified in the event. In case of two identified bottom jets a likelihood function based on the total number of observed events was used. The systematic uncertainties have been treated in a Bayesian approach, all sources of systematic uncertainties have been integrated out. An improved signal modeling using the MadEvent Monte Carlo program matched to NLO calculations has been used. The obtained limits for the s- and t-channel single top production cross sections are 13.6 pb and 10.1 pb, respectively. To date, these are most stringent limits published for the s- and the t-channel single top quark production modes.
Search for Electroweak Single Top Quark Production with Cdf in Proton - Anti-proton Collisions at S**(1/2)
Author: Thorsten Walter
Publisher:
Published: 2005
Total Pages: 157
ISBN-13:
DOWNLOAD EBOOKIn this thesis two searches for electroweak single top quark production with the CDF experiment have been presented, a cutbased search and an iterated discriminant analysis. Both searches find no significant evidence for electroweak single top production using a data set corresponding to an integrated luminosity of 162 pb{sup -1} collected with CDF. Therefore limits on s- and t-channel single top production are determined using a likelihood technique. For the cutbased search a likelihood function based on lepton charge times pseudorapidity of the non-bottom jet was used if exactly one bottom jet was identified in the event. In case of two identified bottom jets a likelihood function based on the total number of observed events was used. The systematic uncertainties have been treated in a Bayesian approach, all sources of systematic uncertainties have been integrated out. An improved signal modeling using the MadEvent Monte Carlo program matched to NLO calculations has been used. The obtained limits for the s- and t-channel single top production cross sections are 13.6 pb and 10.1 pb, respectively. To date, these are most stringent limits published for the s- and the t-channel single top quark production modes.
Observation of Electroweak Single Top-Quark Production with the CDF II Experiment
Author:
Publisher:
Published: 2009
Total Pages: 180
ISBN-13:
DOWNLOAD EBOOKThe standard model of elementary particle physics (SM) predicts, besides the top-quark pair production via the strong interaction, also the electroweak production of single top-quarks [19]. Up to now, the Fermilab Tevatron proton-antiproton-collider is the only place to produce and study top quarks emerging from hadron-hadron-collisions. Top quarks were directly observed in 1995 during the Tevatron Run I at a center-of-mass energy of √s = 1.8 TeV simultaneously by the CDF and D0 Collaborations via the strong production of top-quark pairs. Run II of the Tevatron data taking period started 2001 at √s = 1.96 TeV after a five year upgrade of the Tevatron accelerator complex and of both experiments. One main component of its physics program is the determination of the properties of the top quark including its electroweak production. Even though Run II is still ongoing, the study of the top quark is already a successful endeavor, confirmed by dozens of publications from both Tevatron experiments. A comprehensive review of top-quark physics can be found in reference. The reasons for searching for single top-quark production are compelling. As the electroweak top-quark production proceeds via a Wtb vertex, it provides the unique opportunity of the direct measurement of the CKM matrix element.
Search for Electroweak Single Top-quark Production with the CDF II Experiment
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Published: 2007
Total Pages: 204
ISBN-13:
DOWNLOAD EBOOKUnderstanding the world -- This aim drives humankind since the beginning of conscious thinking. Especially the nature of matter has been of major interest. Nowadays, we have a complex image of the constitution of matter. Atoms consist of electrons and nucleons. But even nucleons are not elementary. Their basic constituents are called quarks. Physicists developed a model describing the elementary components of matter as well as the forces between them: the standard model of elementary particle physics. The substructure of matter is only visible in scattering experiments. In high energy physics, these experiments are done at particle accelerators. The world's highest energetic collider, the Tevatron, is hosted by the Fermi National Accelerator Laboratory (FNAL), also called Fermilab, in the vicinity of Chicago. The proton-antiproton collisions with a center-of-mass energy of (square root)s = 1.96 TeV are recorded by two multipurpose detectors, namely D0 and CDF II.
Search for Electroweak Single Top Quark Production in 1.96 TeV Proton-antiproton Collisions [microform]
Author: Stelzer, Bernd
Publisher: Library and Archives Canada = Bibliothèque et Archives Canada
Published: 2005
Total Pages: 256
ISBN-13: 9780494078129
DOWNLOAD EBOOKThis thesis describes the first search for electroweak single top quark production in proton-antiproton collisions at a center of mass energy of 1.96 TeV. The data sample used for this analysis corresponds to 162 pb -1 recorded by the upgraded Collider Detector at Fermilab. The search is performed by doing a classic maximum likelihood fit to the H T distribution in data. The kinematic variable H T is the scalar sum of transverse energies of all final state particles in the event. This variable has the advantage that its distribution looks very similar for both contributing (s-channel and t-channel) single top processes, but is different for background processes. The combination of both channels to one signal improves the sensitivity of the search. No significant evidence for electroweak single top quark production is found and we set an upper limit at the 95% confidence level on the combined single top quark production cross section of 17.8 pb.
Search for Electroweak Single Top Quark Production in 1.96-TeV Proton-antiproton Collisions
Author: Bernd Stelzer
Publisher:
Published: 2005
Total Pages: 143
ISBN-13:
DOWNLOAD EBOOKThis thesis describes the first search for electroweak single top quark production in proton-antiproton collisions at a center of mass energy of 1.96 TeV. The data sample used for this analysis corresponds to 162 pb{sup -1} recorded by the upgraded Collider Detector at Fermilab. The search is performed by doing a classic maximum likelihood fit to the H{sub T} distribution in data. The kinematic variable H{sub T} is the scalar sum of transverse energies of all final state particles in the event. This variable has the advantage that its distribution looks very similar for both contributing (s-channel and t-channel) single top processes, but is different for background processes. The combination of both channels to one signal improves the sensitivity of the search. No significant evidence for electroweak single top quark production is found and we set an upper limit at the 95% confidence level on the combined single top quark production cross section of 17.8 pb.
Search for Electroweak Single Top Quark Production with CDF.
Author: Y. Kemp
Publisher:
Published: 2005
Total Pages: 4
ISBN-13:
DOWNLOAD EBOOKWe report on a search for Standard Model t-channel and s-channel single top quark production in p{bar p} collisions at a center of mass energy of 1.96 TeV. We use a data sample corresponding to 162 pb{sup -1} recorded by the upgraded Collider Detector at Fermilab. We find no significant evidence for electroweak top quark production and set upper limits at the 95% confidence level on the production cross section, consistent with the Standard Model: 10.1 pb for the t-channel, 13.6 pb for the s-channel and 17.8 pb for the combined cross section of t- and s-channel.
