Measurement of W-boson helicity fractions in top-quark decays using cos theta

Fully reconstructed t over(t, ̄) → W+ b W- over(b, ̄) → ℓ ν q over(q, ̄)′ b over(b, ̄) events are used to determine the fractions of right-handed (f+) and longitudinally polarized (f0) W bosons produced in top-quark decays. The helicity fractions are sensitive to the couplings and the Dirac structur...

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Auteurs principaux: Aaltonen, T, Adelman, J, Akimoto, T, Alvarez Gonzalez, B, Amerio, S, Amidei, D, Anastassov, A, Annovi, A, Antos, J, Apollinari, G, Apresyan, A, Arisawa, T, Artikov, A, Ashmanskas, W, Attal, A, Aurisano, A, Azfar, F, Badgett, W, Barbaro-Galtieri, A, Barnes, V, Barnett, B, Barria, P, Bartsch, V, Bauer, G, Beauchemin, P
Format: Journal article
Langue:English
Publié: 2009
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author Aaltonen, T
Adelman, J
Akimoto, T
Alvarez Gonzalez, B
Amerio, S
Amidei, D
Anastassov, A
Annovi, A
Antos, J
Apollinari, G
Apresyan, A
Arisawa, T
Artikov, A
Ashmanskas, W
Attal, A
Aurisano, A
Azfar, F
Badgett, W
Barbaro-Galtieri, A
Barnes, V
Barnett, B
Barria, P
Bartsch, V
Bauer, G
Beauchemin, P
author_facet Aaltonen, T
Adelman, J
Akimoto, T
Alvarez Gonzalez, B
Amerio, S
Amidei, D
Anastassov, A
Annovi, A
Antos, J
Apollinari, G
Apresyan, A
Arisawa, T
Artikov, A
Ashmanskas, W
Attal, A
Aurisano, A
Azfar, F
Badgett, W
Barbaro-Galtieri, A
Barnes, V
Barnett, B
Barria, P
Bartsch, V
Bauer, G
Beauchemin, P
author_sort Aaltonen, T
collection OXFORD
description Fully reconstructed t over(t, ̄) → W+ b W- over(b, ̄) → ℓ ν q over(q, ̄)′ b over(b, ̄) events are used to determine the fractions of right-handed (f+) and longitudinally polarized (f0) W bosons produced in top-quark decays. The helicity fractions are sensitive to the couplings and the Dirac structure of the Wtb vertex. This Letter reports measurements of the W-boson helicity fractions from two different methods using data corresponding to an integrated luminosity of 1.9 fb- 1 of p over(p, ̄) collisions at a center-of-mass energy of 1.96 TeV collected by the CDF II detector operating at the Fermilab Tevatron. Combining the results from the two methods, we find f0 = 0.62 ± 0.10 (stat) ± 0.05 (syst) under the assumption that f+ = 0, and f+ = - 0.04 ± 0.04 (stat) ± 0.03 (syst) with f0 fixed to the theoretically expected value of 0.70. Model-independent fits are also performed and simultaneously determine f0 = 0.66 ± 0.16 (stat) ± 0.05 (syst) and f+ = - 0.03 ± 0.06 (stat) ± 0.03 (syst). All these results are consistent with standard model expectations. © 2009 Elsevier B.V.
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spelling oxford-uuid:4501c4ae-6e79-4c20-bd18-a64080fc2c7d2022-03-26T15:05:14ZMeasurement of W-boson helicity fractions in top-quark decays using cos thetaJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:4501c4ae-6e79-4c20-bd18-a64080fc2c7dEnglishSymplectic Elements at Oxford2009Aaltonen, TAdelman, JAkimoto, TAlvarez Gonzalez, BAmerio, SAmidei, DAnastassov, AAnnovi, AAntos, JApollinari, GApresyan, AArisawa, TArtikov, AAshmanskas, WAttal, AAurisano, AAzfar, FBadgett, WBarbaro-Galtieri, ABarnes, VBarnett, BBarria, PBartsch, VBauer, GBeauchemin, PFully reconstructed t over(t, ̄) → W+ b W- over(b, ̄) → ℓ ν q over(q, ̄)′ b over(b, ̄) events are used to determine the fractions of right-handed (f+) and longitudinally polarized (f0) W bosons produced in top-quark decays. The helicity fractions are sensitive to the couplings and the Dirac structure of the Wtb vertex. This Letter reports measurements of the W-boson helicity fractions from two different methods using data corresponding to an integrated luminosity of 1.9 fb- 1 of p over(p, ̄) collisions at a center-of-mass energy of 1.96 TeV collected by the CDF II detector operating at the Fermilab Tevatron. Combining the results from the two methods, we find f0 = 0.62 ± 0.10 (stat) ± 0.05 (syst) under the assumption that f+ = 0, and f+ = - 0.04 ± 0.04 (stat) ± 0.03 (syst) with f0 fixed to the theoretically expected value of 0.70. Model-independent fits are also performed and simultaneously determine f0 = 0.66 ± 0.16 (stat) ± 0.05 (syst) and f+ = - 0.03 ± 0.06 (stat) ± 0.03 (syst). All these results are consistent with standard model expectations. © 2009 Elsevier B.V.
spellingShingle Aaltonen, T
Adelman, J
Akimoto, T
Alvarez Gonzalez, B
Amerio, S
Amidei, D
Anastassov, A
Annovi, A
Antos, J
Apollinari, G
Apresyan, A
Arisawa, T
Artikov, A
Ashmanskas, W
Attal, A
Aurisano, A
Azfar, F
Badgett, W
Barbaro-Galtieri, A
Barnes, V
Barnett, B
Barria, P
Bartsch, V
Bauer, G
Beauchemin, P
Measurement of W-boson helicity fractions in top-quark decays using cos theta
title Measurement of W-boson helicity fractions in top-quark decays using cos theta
title_full Measurement of W-boson helicity fractions in top-quark decays using cos theta
title_fullStr Measurement of W-boson helicity fractions in top-quark decays using cos theta
title_full_unstemmed Measurement of W-boson helicity fractions in top-quark decays using cos theta
title_short Measurement of W-boson helicity fractions in top-quark decays using cos theta
title_sort measurement of w boson helicity fractions in top quark decays using cos theta
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