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Measurement of W-boson helicity fractions in top-quark decays using <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si1.gif" overflow="scroll"><mml:mi mathvariant="normal">cos</mml:mi><mml:msup><mml:mi>θ</mml:mi><mml:mo>∗</mml:mo></mml:msup></mml:math>
T. Aaltonen, J. Adelman, T. Akimoto, B. Álvarez González, S. Amerio, D. Amidei, A. Anastassov, A. Annovi, J. Antoš, G. Apollinari, A. Apresyan, T. Arisawa, A. Artikov, W. Ashmanskas, A. Attal, A. Aurisano, F. Azfar, W. Badgett, A. Barbaro‐Galtieri, V. E. Barnes, B. A. Barnett, P. Barria, V. Bartsch, G. Bauer, P. H. Beauchemin, F. Bedeschi, D. Beecher, S. Behari, G. Bellettini, J. Bellinger, D. Benjamin, A. Beretvas, J. Beringer, A. Bhatti, M. Binkley, D. Bisello, I. Bizjak, R. E. Blair, C. Blocker, B. Blumenfeld, A. Bocci, A. Bodek, V. Boisvert, G. Bolla, D. Bortoletto, J. Boudreau, A. Boveia, B. Brau, A. Bridgeman, L. Brigliadori, C. Bromberg, E. Brubaker, J. Budagov, H. S. Budd, S. Budd, S. Bürke, K. Burkett, G. Busetto, P. Bussey, A. Buzatu, K. L. Byrum, C. Calancha, M. Campanelli, M. Campbell, F. Canelli, A. Canepa, B. Carls, D. Carlsmith, R. Carosi, S. Carrillo, S. Carron, B. Casal, M. Casarsa, Andrea Castro, P. Catastini, D. Cauz, V. Cavaliere, F. Šforza, A. Cerri, S. Chang, Y. C. Chen, M. Chertok, G. Chiarelli, G. Chlachidze, F. Chlebana, K. Cho, D. Chokheli, J. P. Chou, G. Choudalakis, S. H. Chuang, K. Chung, W. H. Chung, Y. S. Chung, T. Chwalek, C. I. Ciobanu, M. A. Ciocci, A. Clark, D. Clark, G. Compostella, M. E. Convery, J. Conway, M. Cordelli, G. Cortiana, C. A. Cox, D. J. Cox, F. Crescioli, C. Cuenca Almenar, J. Cuevas, R. Culbertson, J. C. Cully, D. Dagenhart, M. Datta, T. Davies, P. de Barbaro, S. De Cecco, A. Deisher, M. Dell’Orso, C. Deluca, L. Demortier, J. Deng, M. Deninno, P. F. Derwent, A. Di Canto, G. P. Di Giovanni, C. Dionisi, B. Di Ruzza, J. Dittmann, M. D’Onofrio, S. Donati, P. Dong, J. Donini, T. Dorigo, S. Dube, J. Efron, A. Elagin, R. Erbacher, D. Errede, S. Errede, R. Eusebi, H. C. Fang, S. M. Farrington, W. Fedorko, R. G. Feild, M. Feindt, J. P. Fernández, C. Ferrazza, R. D. Field, G. Flanagan, R. Forrest, M. J. Frank, M. Franklin, J. Freeman, I. Furic, M. Gallinaro, J. Galyardt, F. Garberson, F. García, A. F. Garfinkel, P. Garosi, K. Genser, H. Gerberich, D. W. Gerdes, A. Gessler, S. Giagu, V. Giakoumopoulou, P. Giannetti, K. Gibson, J. L. Gimmell, C. M. Ginsburg, N. Giokaris, M. P. Giordani, P. Giromini, M. Giunta, G. Giurgiu, V. Glagolev, D. Glenzinskí, M. Gold, N. Goldschmidt, A. Golossanov, G. Gómez, G. Gomez Ceballos, M. Goncharov, I. Gorelov, A. T. Goshaw, K. Goulianos, A. Gresele, S. Grinstein, C. Grosso-Pilcher, U. Grundler, J. Guimarães da Costa, Z. Gunay-Unalan, C. Haber, K. A. Hahn, S. R. Hahn, E. Halkiadakis, B.-Y. Han, J. Y. Han, F. Happacher, K. Hara, D. Hare, M. Hare, Sam Harper, R. Harr, R. M. Harris, M. Hartz, K. Hatakeyama, C. P. Hays, M. Heck, A. Heijboer, J. J. Heinrich, C. Henderson, M. Herndon, X. He, S. Hewamanage, D. Hidas, C. S. Hill, D. Hirschbuehl, A. Höcker, S. Hou, M. Houlden, S.‐C. Hsu, T. B. Huffman, R. E. Hughes, U. Husemann, M. Hussein, J. Huston, J. Incandela, G. Introzzi, M. Iori, A. Ivanov, E. James, D. Jang, B. Jayatilaka, E. J. Jeon, Manoj K. Jha, S. Jindariani, W. Johnson, M. Jones, K. K. Joo, S. Y. Jun, T. R. Junk, T. Kamon, D. Kar, P. E. Karchin, Y. Kato, R. Kephart, W. Ketchum, J. Keung, V. Khotilovich, B. Kilminster, D. H. Kim, H. S. Kim, H. W. Kim, J.E. Kim, M.J. Kim, S.B. Kim, S. H. Kim, Y. K. Kim, N. Kimura, L. Kirsch, S. Klimenko, B. Knuteson, B. R. Ko, K. Kondo, D. J. Kong, J. Konigsberg, A. Korytov, A. V. Kotwal, M. Kreps, J. Kroll, D. Krop, N. Krumnack, M. Kruse, V. Krutelyov, T. Kubo, T. Kuhr, N. P. Kulkarni, M. Kurata, S. Kwang, A. T. Laasanen, S. Lami, S. Lammel, M. Lancaster, R. L. Lander, K. Lannon, A. Lath, G. Latino, I. Lazzizzera, T. LeCompte, E. Lee, H. S. Lee, S. W. Lee, S. Leone, J. D. Lewis, C. S. Lin, J. Linacre, M. Lindgren, E. Lipeles, A. Lister, D. O. Litvintsev, C. Liu, Tao Liu, A. Loginov, M. Loreti, L. Lovas, D. Lucchesi, C. Luci, J. Lueck, P. Lujan, P. Lukens, G. Lungu, L. Lyons, J. Lys, R. Lysák, D. MacQueen, R. Madrak, K. Maeshima, K. Makhoul, T. Mäki, P. Maksimovic, S. Malde, S. Malik, G. Manca, A. Manousakis-Katsikakis, F. Margaroli, C. P. Marino, A. Martin, M. Martı́nez, R. Mart́ínez-Ballaŕın, T. Maruyama, P. Mastrandrea, T. Masubuchi, M. Mathis, M. E. Mattson, P. Mazzanti, K. S. McFarland, P. McIntyre, R. McNulty, A. Mehta, P. Mehtälä, A. Menzione, P. Merkel, C. Mesropian, T. Miao, N. Miladinovic, Robert F. Miller, C. Mills, M. Milnik, G. Mitselmakher, H. Miyake, S. Moêd, N. Moggi, C. S. Moon, R. W. Moore, M. J. Morello, J. Morlock, P. Movilla Fernandez, J. Mülmenstädt, A. Mukherjee, Th. Müller, R. Mumford, P. Murat, M. Mussini, J. Nachtman, Y. Nagai, A. Nagano, J. Naganoma, K. Nakamura, I. Nakano, A. Napier, V. Necula, J. Nett, C. Neu, M. S. Neubauer, S. Neubauer, J. Nielsen, L. Nodulman, M. Norman, O. Norniella, E. Nurse, L. Oakes, S. H. Oh, Y. D. Oh, I. Oksuzian, T. Okusawa, R. Orava, K. Österberg, S. Pagan Griso, V. Papadimitriou, A. Papaikonomou, A. Paramonov, B. Parks, S. Pashapour, J. Patrick, G. Pauletta, M. Paulini, C. Paus, T. Peiffer, D. E. Pellett, A. Penzo, T. J. Phillips, G. Piacentino, E. Pianori, L. Pinera, K. Pitts, C. Plager, L. Pondrom, O. Poukhov, N. Pounder, F. Prakoshyn, A. Pronko, J. Proudfoot, F. Ptohos, E. Pueschel, G. Punzi, J. Pursley, J. Rademacker, A. Rahaman, V. Ramakrishnan, N. Ranjan, I. Redondo, P. Renton, M. Renz, M. Rescigno, S. Richter, F. Rimondi, L. Ristori, A. Robson, T. Rodrigo, T. Rodriguez, E. Rogers, S. Rolli, R. Roser, M. Rossi, R. Rossin, P. Roy, A. Ruiz-Jimeno, J. Russ, V. Rusu, B. Rutherford, H. Saarikko, A. Safonov, W. K. Sakumoto, O. Saltó, L. Santi, S. Sarkar, L. Sartori, K. Satô, A. Savoy-Navarro, P. Schlabach, A. Schmidt, E. E. Schmidt, M. A. Schmidt, M. P. Schmidt, Michael Henry Schmitt, Thomas Schwarz, L. Scodellaro, A. Scribano, F. Scuri, A. Sedov, S. Seidel, Y. Seiya, A. Semenov, L. Sexton-Kennedy, A. Sfyrla, S. Z. Shalhout, T. Shears, P. F. Shepard, M. Shimojima, S. Shiraishi, M. J. Shochet, Y. Shon, I. Shreyber, P. Sinervo, A. N. Sisakyan, A. J. Slaughter, J. Slaunwhite, K. Śliwa, J. R. Smith, F. D. Snider, R. Snihur, A. Soha, S. Somalwar, V. Sorı́n, T. Spreitzer, P. Squillacioti, M. Stanitzki, R. St. Denis, B. Stelzer, O. Stelzer-Chilton, D. Stentz, J. Strologas, G. L. Strycker, J. S. Suh, A. Sukhanov, I. Suslov, T. Suzuki, A. Taffard, R. Takashima, Y. Takeuchi, R. Tanaka, M. Tecchio, P. K. Teng, K. Terashi, J. Thom, A. S. Thompson, G. A. Thompson, E. Thomson, P. Tipton, P. Ttito-Guzmán, S. Tkaczyk, D. Toback, S. Tokár, K. Tollefson, T. Tomura, D. Tonelli, S. Torre, D. Torretta, P. Totaro, S. Tourneur, M. Trovato, S.-Y. Tsai, Y. Tu, N. Turini, F. Ukegawa, S. Vallecorsa, N. van Remortel, A. Varganov, E. Vataga, F. Vázquez, G. Velev, C. Vellidis, R. Vidal, I. Vila, T. Vine, M. Vogel, I. Volobouev, M. Volpi, P. Wagner, R. G. Wagner, R. L. Wagner, W. Wagner, J. Wagner-Kuhr, T. Wakisaka, R. Wallny, S. M. Wang, A. Warburton, D. Waters, M. Weinberger, J. Weinelt, W. C. Wester, B. Whitehouse, D. Whiteson, A. B. Wicklund, E. Wicklund, S. Wilbur, G. Williams, H. H. Williams, P. Wilson, B. L. Winer, P. Wittich, S. Wolbers, C. Wolfe, T. Wright, X. Wu, F. Würthwein, S. Xie, A. Yagil, K. Yamamoto, J. Yamaoka, U. K. Yang, Y. C. Yang, W.-M. Yao, G. P. Yeh, K. Yi, J. Yoh, K. Yorita, T. Yoshida, G. B. Yu, I. Yu, S. S. Yu, J. C. Yun, L. Zanello, A. Zanetti, X. Zhang, Y. Zheng, S. Zucchelli
Bibliographic record
VenuePhysics Letters B · 2009
Typearticle
Languagelv
FieldPhysics and Astronomy
TopicParticle physics theoretical and experimental studies
Canadian institutionsSimon Fraser University
FundersScience and Technology Facilities Council
KeywordsPhysicsTevatronHelicityParticle physicsTop quarkStandard Model (mathematical formulation)FermilabLuminosityNeutrinoBosonQuarkLeptonNuclear physicsLarge Hadron ColliderElectronQuantum mechanics
Abstract
Fully reconstructed t t ¯ → W + b W − b ¯ → ℓ ν q q ¯ ′ b b ¯ events are used to determine the fractions of right-handed ( f + ) and longitudinally polarized ( f 0 ) 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 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 f 0 = 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 f 0 fixed to the theoretically expected value of 0.70. Model-independent fits are also performed and simultaneously determine f 0 = 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.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
metaresearch head score (Codex)0.001
metaresearch head score (Gemma)0.000
Version: codex-gemma-dda1882f352aValidation status: machine_predicted_unvalidated
Candidate categoriesMeta-epidemiology (narrow), Science and technology studies
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Bench or experimental · Consensus signal: none
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.887
Threshold uncertainty score1.000
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.000 | 0.001 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 0.001 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
Opus teacher head0.022
GPT teacher head0.250
Teacher spread0.228 · how far apart the two teachers sit on this one work
Validation status
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
Study designBench or experimental
Domainnot available
GenreEmpirical
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".
Quick stats
Citations25
Published2009
Admission routes1
Has abstractyes