@article{0888e49cedc24c2b8bef8f628065a916,
title = "Observation of the Semileptonic D+ Decay into the K 1 (1270)0 Axial-Vector Meson",
abstract = "By analyzing a 2.93 fb-1 data sample of e+e- collisions, recorded at a center-of-mass energy of 3.773 GeV with the BESIII detector operated at the BEPCII collider, we report the first observation of the semileptonic D+ transition into the axial-vector meson D+→{\=K}1(1270)0e+νe with a statistical significance greater than 10σ. Its decay branching fraction is determined to be B[D+→{\=K}1(1270)0e+νe]=(2.30±0.26-0.21+0.18±0.25)×10-3, where the first and second uncertainties are statistical and systematic, respectively, and the third originates from the input branching fraction of {\=K}1(1270)0→K-π+π0.",
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 \{Baldini Ferroli\}, R. 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 A. Dbeyssi and D. Dedovich",
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.",
year = "2019",
month = dec,
day = "2",
doi = "10.1103/PhysRevLett.123.231801",
language = "English",
volume = "123",
journal = "Physical Review Letters",
issn = "0031-9007",
publisher = "American Physical Society",
number = "23",
}