Ablikim, M.Achasov, M.N.Adlarson, P.Ahmed, S.Kolcu, Onur Buğra2022-01-192022-01-192021Ablikim, M., Achasov, M. N., Adlarson, P., Ahmed, S., Albrecht, M., Aliberti, R., . . . Zou, J. H. (2021). Observation of the electromagnetic dalitz decay D∗0 →d0e+e-. Physical Review D, 104(11)2470-0010https://doi.org/10.1103/PhysRevD.104.112012https://hdl.handle.net/20.500.12713/2401Based on 3.19 fb-1 of e+e- collision data accumulated at the center-of-mass energy 4.178 GeV with the BESIII detector operating at the BEPCII collider, the electromagnetic Dalitz decay D?0?D0e+e- is observed for the first time with a statistical significance of 13.2?. The ratio of the branching fraction of D?0?D0e+e- to that of D?0?D0? is measured to be (11.08±0.76±0.49)×10-3. By using the world average value of the branching fraction of D?0?D0?, the branching fraction of D?0?D0e+e- is determined to be (3.91±0.27±0.17±0.10)×10-3, where the first uncertainty is statistical, the second is systematic and the third is from external input of the branching fraction for D?0?D0?. © 2021 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 SCOAP3.eninfo:eu-repo/semantics/openAccessArticle10411WOS:0007468487000062-s2.0-85122402930Q110.1103/PhysRevD.104.112012Q1