@article{a4169c509b034090866c3ff39e1a5283,
title = "Observation of the double Dalitz decay η′ →e+e-e+e-",
abstract = "Based on (10087±44)×106 J/ψ events collected with the BESIII detector at BEPCII, the double Dalitz decay η′→e+e-e+e-is observed for the first time via the J/ψ→γη′ decay process. The significance is found to be 5.7σ with systematic uncertainties taken into consideration. Its branching fraction is determined to be B(η′→e+e-e+e-)=(4.5±1.0(stat)±0.5(sys))×10-6. ",
author = "{BESIII Collaboration} and M. Ablikim and Achasov, {M. N.} and P. Adlarson and M. Albrecht and R. Aliberti and A. Amoroso and An, {M. R.} and Q. An and Bai, {X. H.} and Y. Bai and O. Bakina and {Baldini Ferroli}, R. and I. Balossino and Y. Ban and V. Batozskaya and D. Becker and K. Begzsuren and N. Berger and M. Bertani and D. Bettoni and F. Bianchi and J. Bloms and A. Bortone and I. Boyko and Briere, {R. A.} and A. Brueggemann and H. Cai and X. Cai and A. Calcaterra and Cao, {G. F.} and N. Cao and Cetin, {S. A.} and Chang, {J. F.} and Chang, {W. L.} and G. Chelkov and C. Chen and Chao Chen and G. Chen and Chen, {H. S.} and Chen, {M. L.} and Chen, {S. J.} and Chen, {S. M.} and Chen, {X. T.} and Chen, {X. R.} and Chen, {X. T.} and Chen, {Y. B.} and Chen, {Z. J.} and Cheng, {W. S.} and Muchnoi, {N. Yu} and Nikolaev, {I. B.}",
note = "Funding Information: The BESIII Collaboration thanks the staff of BEPCII and the IHEP computing center for their strong support. We thank Feng Xu for useful discussions. This work is supported in part by National Key R&D Program of China under Contracts No. 2020YFA0406400 and No. 2020YFA0406300; National Natural Science Foundation of China (NSFC) under Contracts No. 11625523, No. 11635010, No. 11735014, No. 11822506, No. 11835012, No. 11935015, No. 11935016, No. 11935018, No. 11961141012, No. 12022510, No. 12025502, No. 12035009, No. 12035013, No. 12061131003, and No. 12165022; the Chinese Academy of Sciences (CAS) Large-Scale Scientific Facility Program; Joint Large-Scale Scientific Facility Funds of the NSFC and CAS under Contracts No. U1732263 and No. U1832207; CAS Key Research Program of Frontier Sciences under Contract No. QYZDJ-SSW-SLH040; 100 Talents Program of CAS; INPAC and Shanghai Key Laboratory for Particle Physics and Cosmology; ERC under Contract No. 758462; European Union Horizon 2020 research and innovation program under Marie Sklodowska-Curie Grant Agreement No. 894790; German Research Foundation DFG under Contract No. 443159800, Collaborative Research Center CRC 1044, FOR 2359, GRK 214; Istituto Nazionale di Fisica Nucleare, Italy; Ministry of Development of Turkey under Contract No. DPT2006K-120470; National Science and Technology fund; Olle Engkvist Foundation under Contract No. 200-0605; STFC (United Kingdom); The Knut and Alice Wallenberg Foundation (Sweden) under Contract No. 2016.0157; The Royal Society, UK under Contracts No. DH140054 and DH160214; The Swedish Research Council; U.S. Department of Energy under Awards No. DE-FG02-05ER41374 and No. DE-SC-0012069. Publisher Copyright: {\textcopyright} 2022 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.",
year = "2022",
month = jun,
day = "1",
doi = "10.1103/PhysRevD.105.112010",
language = "English",
volume = "105",
journal = "Physical Review D",
issn = "2470-0010",
publisher = "AMER PHYSICAL SOC",
number = "11",
}