Search for lepton-flavor-violating tau decays to ℓα at Belle
A bstract We report a search for the lepton-flavor-violating decays τ ± → ℓ ± α ( ℓ = e , μ ), where α is an undetected spin-0 particle, such as an axion-like particle using 736 × 10 6 tau lepton pairs collected by the Belle detector at the KEKB asymmetric-energy e + e − collider. We find no evidence of signal and obtain the most stringent upper limits on the branching fractions at 95% confidence level: $$\mathcal{B}$$ ( τ ± → e ± α ) < (0.4–6.4) × 10 − 4 and $$\mathcal{B}$$ ( τ ± → μ ± α ) < (0.2–3.5) × 10 − 4 at 95% confidence level for an α mass in the range 0.0 ≤ m α ≤ 1.6 GeV/ c 2 .
Authors
- T. Lam (ORCID: https://orcid.org/0000-0001-9128-6806)
- K. Kinoshita (ORCID: https://orcid.org/0000-0001-7175-4182)
- L. Li Gioi (ORCID: https://orcid.org/0000-0003-2024-5649)
- T. E. Browder (ORCID: https://orcid.org/0000-0001-7357-9007)
- P. Ecker (ORCID: https://orcid.org/0000-0002-6817-6868)
- S. Pardi (ORCID: https://orcid.org/0000-0001-7994-0537)
- C. H. Kim (ORCID: https://orcid.org/0000-0002-5743-7698)
- C. Z. Yuan (ORCID: https://orcid.org/0000-0002-1652-6686)
- Z. P. Zhang (ORCID: https://orcid.org/0000-0001-6140-2044)
- D. Ricalde Herrmann (ORCID: https://orcid.org/0000-0001-9772-9989)
- C. Schwanda (ORCID: https://orcid.org/0000-0003-4844-5028)
- D. Epifanov (ORCID: https://orcid.org/0000-0001-8656-2693)
- J. Libby (ORCID: https://orcid.org/0000-0002-1219-3247)
- K. Kumara (ORCID: https://orcid.org/0000-0003-1572-5365)
- S. Uehara (ORCID: https://orcid.org/0000-0001-7377-5016)
- Y.-J. Kwon (ORCID: https://orcid.org/0000-0001-9448-5691)
- Y. B. Li (ORCID: https://orcid.org/0000-0002-9909-2851)
- G. Russo (ORCID: https://orcid.org/0000-0001-5823-4393)
- S. Patra (ORCID: https://orcid.org/0000-0002-4114-1091)
- S.-H. Park (ORCID: https://orcid.org/0000-0001-6019-6218)
- S. Paul (ORCID: https://orcid.org/0000-0002-8813-0437)
- A. Ishikawa (ORCID: https://orcid.org/0000-0002-3561-5633)
- Y. Jin (ORCID: https://orcid.org/0000-0002-7323-0830)
- E. Graziani (ORCID: https://orcid.org/0000-0001-8602-5652)
- J. V. Bennett (ORCID: https://orcid.org/0000-0002-5440-2668)
- J. B. Singh (ORCID: https://orcid.org/0000-0001-9029-2462)
- H. Aihara (ORCID: https://orcid.org/0000-0002-1907-5964)
- M. Masuda (ORCID: https://orcid.org/0000-0002-7109-5583)
- Y. Seino (ORCID: https://orcid.org/0000-0002-8378-4255)
- B. Shwartz (ORCID: https://orcid.org/0000-0002-1456-1496)
- A. Natochii (ORCID: https://orcid.org/0000-0002-1076-814X)
- T. K. Pedlar (ORCID: https://orcid.org/0000-0001-9839-7373)
- S. Korpar (ORCID: https://orcid.org/0000-0003-0971-0968)
- R. Itoh (ORCID: https://orcid.org/0000-0003-1590-0266)
- M. Niiyama (ORCID: https://orcid.org/0000-0003-1746-586X)
- K. Miyabayashi (ORCID: https://orcid.org/0000-0003-4352-734X)
- P. Kodyš (ORCID: https://orcid.org/0000-0002-8644-2349)
- K. Belous (ORCID: https://orcid.org/0000-0003-0014-2589)
- H. Ono (ORCID: https://orcid.org/0000-0003-4486-0064)
- F. Di Capua (ORCID: https://orcid.org/0000-0001-9076-5936)
- J. Park (ORCID: https://orcid.org/0000-0001-6520-0028)
- S. Sandilya (ORCID: https://orcid.org/0000-0002-4199-4369)
- F. Simon (ORCID: https://orcid.org/0000-0002-5978-0289)
- D. Y. Kim (ORCID: https://orcid.org/0000-0001-8125-9070)
- K. Hayasaka (ORCID: https://orcid.org/0000-0002-6347-433X)
- E. Solovieva (ORCID: https://orcid.org/0000-0002-5735-4059)
- Y. Choi (ORCID: https://orcid.org/0000-0003-3499-7948)
- G. De Pietro (ORCID: https://orcid.org/0000-0001-8442-107X)
- P. Branchini (ORCID: https://orcid.org/0000-0002-2270-9673)
- M.-Z. Wang (ORCID: https://orcid.org/0000-0002-0979-8341)
- T. Podobnik (ORCID: https://orcid.org/0000-0002-6131-819X)
- Y. Guan (ORCID: https://orcid.org/0000-0002-5541-2278)
- M. Bessner (ORCID: https://orcid.org/0000-0003-1776-0439)
- A. Korobov (ORCID: https://orcid.org/0000-0001-5959-8172)
- D. Liventsev (ORCID: https://orcid.org/0000-0003-3416-0056)
- P. Goldenzweig (ORCID: https://orcid.org/0000-0001-8785-847X)
- S. Ogawa (ORCID: https://orcid.org/0000-0002-7310-5079)
- S.-K. Choi (ORCID: https://orcid.org/0000-0003-2747-8277)
- D. Biswas (ORCID: https://orcid.org/0000-0002-7543-3471)
- Z. Doležal (ORCID: https://orcid.org/0000-0002-5662-3675)
- Y. Yusa (ORCID: https://orcid.org/0000-0002-4001-9748)
- D. Bodrov (ORCID: https://orcid.org/0000-0001-5279-4787)
- Y. Yook (ORCID: https://orcid.org/0000-0002-4912-048X)
- S. Nishida (ORCID: https://orcid.org/0000-0001-6373-2346)
- K. Gudkova (ORCID: https://orcid.org/0000-0002-5858-3187)
- C.-L. Hsu (ORCID: https://orcid.org/0000-0002-1641-430X)
- J.-G. Shiu
- S. Prell (ORCID: https://orcid.org/0000-0002-0195-8005)
- K.-H. Kim (ORCID: https://orcid.org/0000-0002-4659-1112)
- L. K. Li (ORCID: https://orcid.org/0000-0002-7366-1307)
- M. Campajola (ORCID: https://orcid.org/0000-0003-2518-7134)
- A. Kuzmin (ORCID: https://orcid.org/0000-0002-7011-5044)
- J. Dingfelder (ORCID: https://orcid.org/0000-0001-5767-2121)
- E. Won (ORCID: https://orcid.org/0000-0002-4245-7442)
- G. De Nardo (ORCID: https://orcid.org/0000-0002-2047-9675)
- E. Kovalenko (ORCID: https://orcid.org/0000-0001-8084-1931)
- S. Choudhury (ORCID: https://orcid.org/0000-0001-9841-0216)
- Y. Unno (ORCID: https://orcid.org/0000-0003-3355-765X)
- M. Takizawa (ORCID: https://orcid.org/0000-0001-8225-3973)
- M. Sumihama (ORCID: https://orcid.org/0000-0002-8954-0585)
- K. Uno (ORCID: https://orcid.org/0000-0002-2209-8198)
- W. W. Jacobs (ORCID: https://orcid.org/0000-0002-9996-6336)
- M. Iwasaki
- C. Kiesling (ORCID: https://orcid.org/0000-0002-2209-535X)
- Kiyoshi Tanida (ORCID: https://orcid.org/0000-0002-8255-3746)
- T. Uglov (ORCID: https://orcid.org/0000-0002-4944-1830)
- A. Budano (ORCID: https://orcid.org/0000-0002-0856-1131)
- T. Hara (ORCID: https://orcid.org/0000-0002-4321-0417)
- D. Matvienko (ORCID: https://orcid.org/0000-0002-2698-5448)
- K. Senyo (ORCID: https://orcid.org/0000-0002-1615-9118)
- A. Giri (ORCID: https://orcid.org/0000-0002-8895-0128)
- B. Yabsley (ORCID: https://orcid.org/0000-0002-2680-0474)
- H. Hayashii (ORCID: https://orcid.org/0000-0002-5138-5903)
- W. Shan (ORCID: https://orcid.org/0000-0003-2811-2218)
- P. Krokovny (ORCID: https://orcid.org/0000-0002-1236-4667)
- L. Šantelj (ORCID: https://orcid.org/0000-0003-3904-2956)
- C. Hadjivasiliou (ORCID: https://orcid.org/0000-0002-2234-0001)
- K. Cho (ORCID: https://orcid.org/0000-0003-1705-7399)
- E. Prencipe (ORCID: https://orcid.org/0000-0002-9465-2493)
- V. Zhilich (ORCID: https://orcid.org/0000-0002-0907-5565)
- T. Matsuda (ORCID: https://orcid.org/0000-0003-4673-570X)
- F. Tenchini (ORCID: https://orcid.org/0000-0003-3469-9377)
- N. Ipsita (ORCID: https://orcid.org/0000-0002-2927-3366)
- S. Uno (ORCID: https://orcid.org/0000-0002-3401-0480)
- B. G. Fulsom (ORCID: https://orcid.org/0000-0002-5862-9739)
- M. T. Prim (ORCID: https://orcid.org/0000-0002-1407-7450)
- R. Ayad (ORCID: https://orcid.org/0000-0003-3466-9290)
- V. Savinov (ORCID: https://orcid.org/0000-0002-9184-2830)
- G. B. Mohanty (ORCID: https://orcid.org/0000-0001-6850-7666)
- L. Yuan (ORCID: https://orcid.org/0000-0002-6719-5397)
- R. Kumar (ORCID: https://orcid.org/0000-0002-6277-2626)
- F. Meier (ORCID: https://orcid.org/0000-0002-6088-0412)
- M. Nakao (ORCID: https://orcid.org/0000-0001-8424-7075)
- H. Nakazawa (ORCID: https://orcid.org/0000-0003-1684-6628)
- M. Starič
- L. E. Piilonen (ORCID: https://orcid.org/0000-0001-6836-0748)
- K. Inami (ORCID: https://orcid.org/0000-0003-2765-7072)
- M. Merola (ORCID: https://orcid.org/0000-0002-7082-8108)
- V. Gaur (ORCID: https://orcid.org/0000-0002-8880-6134)
- T. Ferber (ORCID: https://orcid.org/0000-0002-6849-0427)
- M. Bračko (ORCID: https://orcid.org/0000-0002-2495-0524)
- S. Banerjee (ORCID: https://orcid.org/0000-0001-8852-2409)
- K. Trabelsi (ORCID: https://orcid.org/0000-0001-6567-3036)
- G. Schnell (ORCID: https://orcid.org/0000-0002-7336-3246)
- Yue Ma (ORCID: https://orcid.org/0000-0001-8412-8308)
Institutions
- Korea Electric Power Corporation (South Korea) (KR)
Publication Details
- Journal
- Journal of High Energy Physics
- Published
- 2025-08-20
- DOI
- https://doi.org/10.1007/jhep08(2025)155
- Citations
- 1
- Primary Topic
- Particle physics theoretical and experimental studies
- Type
- article
- Field-Weighted Citation Impact
- 1.87
Funders
- National Science Foundation
- U.S. Department of Energy
- University of Tabuk
- European Commission
- National Research Foundation
- Deutsche Forschungsgemeinschaft
- Volkswagen Foundation
- Ministry of Education, Culture, Sports, Science and Technology
- Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung
- National Natural Science Foundation of China
- Grantová Agentura České Republiky
- Austrian Science Fund
- Korea Institute of Science and Technology
- Korea Institute of Science and Technology Information
- Ikerbasque, Basque Foundation for Science
- Javna Agencija za Raziskovalno Dejavnost RS
- Ministerio de Ciencia e Innovación
- Natural Science Foundation of Shandong Province
- National Research University Higher School of Economics
- Ministry of Science and Higher Education of the Russian Federation
- Istituto Nazionale di Fisica Nucleare
- Bundesministerium für Bildung, Wissenschaft und Forschung
- National Science and Technology Council
- Korea Research Environment Open Network
- Japan Society for the Promotion of Science