TY - JOUR

T1 - Measurement of the branching fraction of D+ → τ+ντ

AU - BESIII Collaboration

AU - Ablikim, M.

AU - Achasov, M. n.

AU - Adlarson, P.

AU - Afedulidis, O.

AU - Ai, X. c.

AU - Aliberti, R.

AU - Amoroso, A.

AU - Bai, Y.

AU - Bakina, O.

AU - Balossino, I.

AU - Ban, Y.

AU - Bao, H.-R.

AU - Batozskaya, V.

AU - Begzsuren, K.

AU - Berger, N.

AU - Berlowski, M.

AU - Bertani, M.

AU - Bettoni, D.

AU - Bianchi, F.

AU - Bianco, E.

AU - Bortone, A.

AU - Boyko, I.

AU - Briere, R. a.

AU - Brueggemann, A.

AU - Cai, H.

AU - Cai, X.

AU - Мучной, Николай Юрьевич

AU - Николаев, Иван Борисович

N1 - The BESIII Collaboration thanks the staff of BEPCII and the IHEP computing center for their strong support. This work is supported in part by National Key R&D Program of China under Contracts Nos. 2023YFA1606000, 2020YFA0406400, 2020YFA0406300; National Natural Science Foundation of China (NSFC) under Contracts Nos. 11635010, 11735014, 11935015, 11935016, 11935018, 12025502, 12035009, 12035013, 12061131003, 12192260, 12192261, 12192262, 12192263, 12192264, 12192265, 12221005, 12225509, 12235017, 12361141819, 12305105; the Chinese Academy of Sciences (CAS) Large-Scale Scientific Facility Program; the CAS Center for Excellence in Particle Physics (CCEPP); Joint Large-Scale Scientific Facility Funds of the NSFC and CAS under Contract No. U2032104, U1832207; The Excellent Youth Foundation of Henan Scientific Committee under Contract No. 242300421044; Natural Science Foundation of Shandong Province under Grants No. ZR2023QA119; 100 Talents Program of CAS; The Institute of Nuclear and Particle Physics (INPAC) and Shanghai Key Laboratory for Particle Physics and Cosmology; German Research Foundation DFG under Contracts Nos. FOR5327, GRK 2149; Istituto Nazionale di Fisica Nucleare, Italy; Knut and Alice Wallenberg Foundation under Contracts Nos. 2021.0174, 2021.0299; Ministry of Development of Turkey under Contract No. DPT2006K-120470; National Research Foundation of Korea under Contract No. NRF-2022R1A2C1092335; National Science and Technology fund of Mongolia; National Science Research and Innovation Fund (NSRF) via the Program Management Unit for Human Resources & Institutional Development, Research and Innovation of Thailand under Contracts Nos. B16F640076, B50G670107; Polish National Science Centre under Contract No. 2019/35/O/ST2/02907; Swedish Research Council under Contract No. 2019.04595; The Swedish Foundation for International Cooperation in Research and Higher Education under Contract No. CH2018-7756; U. S. Department of Energy under Contract No. DE-FG02-05ER41374.

PY - 2025

Y1 - 2025

N2 - By analyzing e+e− collision data with an integrated luminosity of 7.9 fb−1 collected with the BESIII detector at the center-of-mass energy of 3.773 GeV, the branching fraction of D+ → τ+ντ is determined as = (9.9 ± 1.1stat ± 0.5syst) × 10−4. Using the most precise result (D+ → μ+νμ) = (3.981 ± 0.079stat ± 0.040syst) × 10−4 [1], we determine Rτ/μ = Γ(D+ → τ+ντ)/Γ(D+ → μ+νμ) = 2.49 ± 0.31, achieving a factor of two improvement in precision compared to the previous BESIII result. This measurement is in agreement with the standard model prediction of lepton flavor universality within one standard deviation.

AB - By analyzing e+e− collision data with an integrated luminosity of 7.9 fb−1 collected with the BESIII detector at the center-of-mass energy of 3.773 GeV, the branching fraction of D+ → τ+ντ is determined as = (9.9 ± 1.1stat ± 0.5syst) × 10−4. Using the most precise result (D+ → μ+νμ) = (3.981 ± 0.079stat ± 0.040syst) × 10−4 [1], we determine Rτ/μ = Γ(D+ → τ+ντ)/Γ(D+ → μ+νμ) = 2.49 ± 0.31, achieving a factor of two improvement in precision compared to the previous BESIII result. This measurement is in agreement with the standard model prediction of lepton flavor universality within one standard deviation.

UR - https://www.scopus.com/record/display.uri?eid=2-s2.0-86000465399&origin=inward&txGid=39ef80997ff5d190bd29aff7d687e9f0

U2 - 10.1007/JHEP01(2025)089

DO - 10.1007/JHEP01(2025)089

M3 - Article

VL - 2025

JO - Journal of High Energy Physics

JF - Journal of High Energy Physics

SN - 1029-8479

IS - 1

M1 - 89

ER -