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...
| Main Authors: | , , , , , , , , , , , , , , , , , , , , , , , , |
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| Format: | Journal article |
| Language: | English |
| Published: |
2009
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| _version_ | 1826269878558916608 |
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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. |
| first_indexed | 2024-03-06T21:32:05Z |
| format | Journal article |
| id | oxford-uuid:4501c4ae-6e79-4c20-bd18-a64080fc2c7d |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-06T21:32:05Z |
| publishDate | 2009 |
| record_format | dspace |
| 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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