@article{f7844e604b41416988d217b04bd6833e,
title = "Observation of the Leptonic Decay D+ →τ+ντ",
abstract = "We report the first observation of D+→τ+ντ with a significance of 5.1σ. We measure B(D+→τ+ντ)=(1.20±0.24stat±0.12syst)×10-3. Taking the world average B(D+→μ+νμ)=(3.74±0.17)×10-4, we obtain Rτ/μ=Γ(D+→τ+ντ)/Γ(D+→μ+νμ)=3.21±0.64stat±0.43syst., which is consistent with the standard model expectation of lepton flavor universality. Using external inputs, our results give values for the D+ decay constant fD+ and the Cabibbo-Kobayashi-Maskawa matrix element |Vcd| that are consistent with, but less precise than, other determinations.",
author = "{BESIII Collaboration} and M. Ablikim and Achasov, {M. N.} and P. Adlarson and S. Ahmed and M. Albrecht and M. Alekseev and A. Amoroso and An, {F. F.} and Q. An and Y. Bai and O. Bakina and Ferroli, {R. Baldini} and I. Balossino and Y. Ban and K. Begzsuren and Bennett, {J. V.} and N. Berger and M. Bertani and D. Bettoni and F. Bianchi and J. Biernat and J. Bloms and I. Boyko and Briere, {R. A.} and H. Cai and X. Cai and A. Calcaterra and Cao, {G. F.} and N. Cao and Cetin, {S. A.} and J. Chai and Chang, {J. F.} and Chang, {W. L.} and G. Chelkov and Chen, {D. Y.} and G. Chen and Chen, {H. S.} and Chen, {J. C.} and Chen, {M. L.} and Chen, {S. J.} and Chen, {Y. B.} and W. Cheng and G. Cibinetto and F. Cossio and Cui, {X. F.} and Dai, {H. L.} and Dai, {J. P.} and Dai, {X. C.} and Muchnoi, {N. Yu} and Nikolaev, {I. B.}",
note = "Publisher Copyright: {\textcopyright} 2019 authors. Published by the American Physical Society. Published by the American Physical Society under the terms of the {"}https://creativecommons.org/licenses/by/4.0/{"} Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI. Funded by SCOAP . Copyright: Copyright 2019 Elsevier B.V., All rights reserved.",
year = "2019",
month = nov,
day = "22",
doi = "10.1103/PhysRevLett.123.211802",
language = "English",
volume = "123",
journal = "Physical Review Letters",
issn = "0031-9007",
publisher = "American Physical Society",
number = "21",
}