← Back to cohort
First Measurement of $R(X_{τ/\ell})$ as an Inclusive Test of the $b \to c τν$ Anomaly
I. Adachi, K. Adamczyk, L. Aggarwal, H. Ahmed, H. Aihara, Н. Акопов, A. Aloisio, D. M. Asner, H. Atmacan, T. Aushev, V. Aushev, M. Aversano, V. Babu, S. Bahinipati, P. Bambade, Sw. Banerjee, S. Bansal, M. Barrett, J. Baudot, A. Baur, A. Beaubien, F. Becherer, Jürgen Becker, J. V. Bennett, F. U. Bernlochner, V. Bertacchi, M. Bertemes, E. Bertholet, M. Bessner, S. Bettarini, B. Bhuyan, F. Bianchi, T. Bilka, S. Bilokin, D. Biswas, A. Bobrov, D. Bodrov, A. E. Bolz, A. Bondar, A. Bożek, M. Bračko, P. Branchini, R. A. Briere, T. E. Browder, A. Budano, S. Bussino, M. Campajola, L. Cao, G. Casarosa, C. Cecchi, J. Cerasoli, P. Chang, P. Cheema, B. G. Cheon, K. Chilikin, K. Chirapatpimol, K. Cho, S. -J. Cho, S. Choudhury, L. Corona, L. Cremaldi, F. Dattola, E. De La Cruz–Burelo, S. A. De La Motte, G. de Marino, G. De Nardo, M. De Nuccio, G. De Pietro, R. de Sangro, M. Destefanis, R. Dhamija, A. Di Canto, F. Di Capua, J. Dingfelder, Z. Doležal, T. V. Dong, M. Dorigo, K. Dort, S. Dreyer, S. Dubey, G. Dujany, P. Ecker, M. Eliachevitch, D. Epifanov, P. Feichtinger, T. Ferber, D. Ferlewicz, T. Fillinger, G. Finocchiaro, A. Fodor, F. Forti, A. Frey, B. G. Fulsom, E. Ganiev, M. Garcia-Hernandez, Renu Garg, G. Gaudino, V. Gaur, A. Gaz, A. Gellrich, G. Ghevondyan, D. Ghosh, H. Ghumaryan, G. Giakoustidis, R. Giordano, A. Giri, B. Gobbo, R. Godang, O. Gogota, P. Goldenzweig, W. Gradl, T. Grammatico, E. Graziani, D. Greenwald, Z. Gruberová, T. Gu, K. Gudkova, S. Halder, Y. L. Han, Takanori Hara, H. Hayashii, S. Hazra, C. Hearty, M. T. Hedges, A. Heidelbach, I. Heredia-De La Cruz, T. Higuchi, M. Hoek, M. Hohmann, P. Horak, T. Humair, T. Iijima, N. Ipsita, A. Ishikawa, R. Itoh, M. Iwasaki, P. Jackson, W. W. Jacobs, D. E. Jaffe, S. Jia, Yuxia Jin, K. K. Joo, H. Junkerkalefeld, D. Kalita, J. Kandra, K. H. Kang, G. Karyan, T. Kawasaki, F. Keil, C. Kiesling, D. Y. Kim, K. -H. Kim, K. Kinoshita, T. Koga, S. Kohani, K. Kojima, A. Korobov, S. Korpar, E. Kovalenko, R. Kowalewski, T. M. G. Kraetzschmar, P. Križan, P. Krokovny, T. Kuhr, Y. Kulii, M. Kumar, T. Kunigo, A. Kuzmin, S. Lacaprara, T. Lam, L. Lanceri, J. S. Lange, M. Laurenza, R. Leboucher, M. J. Lee, D. Levit, P. Lewis, L. K. Li, Y. Li, Y. B. Li, J. Libby, M. Liu, Q. Y. Liu, Z. Q. Liu, D. Liventsev, S. Longo, T. Lueck, T. Luo, C. Lyu, Yao Ma, M. Maggiora, S. P. Maharana, R. Maiti, S. Maity, G. Mancinelli, R. Manfredi, E. Manoni, A. C. Manthei, M. Mantovano, D. Marcantonio, C. Mariñas, L. Martel, C. Martellini, T. Martinov, L. Massaccesi, M. Masuda, T. Matsuda, D. Matvienko, S. K. Maurya, J. A. McKenna, R. Mehta, F. Meier, M. Merola, F. Metzner, M. Milesi, C. Miller, M. Mirra, K. Miyabayashi, H. Miyake, R. Mizuk, G. B. Mohanty, N. Molina-Gonzalez, S. Mondal, S. Moneta, M. Mrvar, R. Mussa, I. Nakamura, M. Nakao, Y. Nakazawa, M. Naruki, D. Narwal, Z. Natkaniec, A. Natochii, L. Nayak, M. Nayak, G. Nazaryan, S. Nishida, H. Ono, Y. Onuki, P. Oskin, P. Pakhlov, G. Pakhlova, A. Panta, S. Pardi, H. Park, B. Paschen, A. Passeri, S. Patra, S. Paul, T. K. Pedlar, R. Peschke, R. Pestotnik, M. Piccolo, L. E. Piilonen, P. L. M. Podesta-Lerma, T. Podobnik, S. Pokharel, C. Praz, S. Prell, E. Prencipe, M. T. Prim, H. Purwar, P. Rados, G. Raeuber, S. Raiz, N. Rauls, M. Reif, S. Reiter, I. Ripp-Baudot, G. Rizzo, S. H. Robertson, P. Rocchetti, M. Röhrken, J. M. Roney, A. Rostomyan, N. Rout, G. Russo, Y. Sakai, D. A. Sanders, S. Sandilya, L. Santelj, Y. Sato, V. Savinov, B. Scavino, C. Schmitt, C. Schwanda, Y. Seino, A. Selce, K. Senyo, J. Serrano, M. E. Sevior, C. Sfienti, W. Shan, C. P. Shen, X. Shi, T. Shillington, T. Shimasaki, D. Shtol, A. Sibidanov, F. Simon, J. B. Singh, J. Skorupa, R. Sobie, M. Sobotzik, A. Soffer, A. Sokolov, E. Solovieva, S. Spataro, B. Spruck, M. Starič, P. Stavroulakis, S. Stefkova, R. Stroili, M. Sumihama, K. Sumisawa, H. Svidras, U. Tamponi, S. Tanaka, K. Tanida, F. Tenchini, O. Tittel, R. Tiwary, D. Tonelli, E. Torassa, K. Trabelsi, I. Tsaklidis, M. Uchida, I. Ueda, Y. Uematsu, T. Uglov, K. Unger, Y. Unno, K. Uno, S. Uno, P. Urquijo, Y. Ushiroda, S. Vahsen, R. van Tonder, K. E. Varvell, M. Veronesi, A. Vinokurova, V. S. Vismaya, L. Vitale, R. Volpe, B. Wach, M. Wakai, S. Wallner, X. L. Wang, Z. Wang, A. Warburton, S. Watanuki, C. Wessel, E. Won, X. P. Xu, B. Yabsley, S. Yamada, S. B. Yang, J. Yelton, J. H. Yin, K. Yoshihara, C. Z. Yuan, B. Zhang, Y. Zhang, V. Zhilich, Q. Zhou, X. Y. Zhou, V. Zhukova
Bibliographic record
VenuearXiv (Cornell University) · 2023
Typepreprint
Languageen
FieldPhysics and Astronomy
TopicParticle physics theoretical and experimental studies
Canadian institutionsnot available
FundersInstitut National de Physique Nucléaire et de Physique des ParticulesAkademi Sains MalaysiaJapan Society for the Promotion of ScienceNatural Sciences and Engineering Research Council of CanadaKorea Research Environment Open NetworkCentro de Investigación y de Estudios Avanzados del Instituto Politécnico NacionalIstituto Nazionale di Fisica NucleareMinistry of Science and Higher Education of the Russian FederationNational Research University Higher School of EconomicsJavna Agencija za Raziskovalno Dejavnost RSMinistry of Education, Culture, Sports, Science and TechnologyKorea Institute of Science and Technology InformationNational Research FoundationAustrian Science FundU.S. Department of EnergyNational Natural Science Foundation of ChinaDeutsche ForschungsgemeinschaftMax-Planck-GesellschaftNational Research Foundation of UkraineNational Institute of InformaticsGrantová Agentura České RepublikyDeutsches Elektronen-SynchrotronGeneralitat ValencianaThailand Center of Excellence in PhysicsAlexander von Humboldt-StiftungBundesministerium für Bildung, Wissenschaft und ForschungMinistry of Education and Science of UkraineVietnam Academy of Science and TechnologyNatural Science Foundation of Shandong ProvinceCompute CanadaUniversity of TabukNational Science FoundationKorea Institute of Science and TechnologyBundesministerium für Bildung und ForschungCanarieTürkiye Bilimsel ve Teknolojik Araştırma KurumuAgence Nationale de la RechercheGrantová Agentura, Univerzita KarlovaCentre National de la Recherche ScientifiqueUniverzita Karlova v PrazeNational Science and Technology CouncilUniversity of Victoria
KeywordsPhysicsLeptonMuonParticle physicsUniversality (dynamical systems)B mesonElectron–positron annihilationAnomaly (physics)MesonElectronNuclear physicsHadronQuantum mechanics
Abstract
We measure the tau-to-light-lepton ratio of inclusive $B$-meson branching fractions $R(X_{τ/\ell}) \equiv \mathcal{B}(B\to X τν)/\mathcal{B}(B \to X \ell ν)$, where $\ell$ indicates an electron or muon, and thereby test the universality of charged-current weak interactions. We select events that have one fully reconstructed $B$ meson and a charged lepton candidate from $189~\mathrm{fb}^{-1}$ of electron-positron collision data collected with the Belle II detector. We find $R(X_{τ/\ell}) = 0.228 \pm 0.016~(\mathrm{stat}) \pm 0.036~(\mathrm{syst})$, in agreement with standard-model expectations. This is the first direct measurement of $R(X_{τ/\ell})$.
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 machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
metaresearch head score (Codex)0.001
metaresearch head score (Gemma)0.002
Version: metacan-v3-hybrid-931329e0061cValidation status: machine_predicted_unvalidated
Candidate categoriesnone
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Observational · Consensus signal: none
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.003
Threshold uncertainty score0.011
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.002 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.003 | 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 head0.065
GPT teacher head0.214
Teacher spread0.149 · 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 source (direct Gemma or distilled Codex), not a consensus.
The models applied no category: nothing in the taxonomy fit this work.
Study designObservational
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
Citations5
Published2023
Admission routes1
Has abstractyes