TY - JOUR
T1 - First direct measurement of the absolute branching fraction of ς+ → Λe+νe
AU - BESIII Collaboration
AU - Ablikim, M.
AU - Achasov, M. N.
AU - Kalantar-Nayestanaki, N.
AU - Kappert, R.
AU - Kavatsyuk, M.
AU - Messchendorp, J.
AU - Rodin, V.
N1 - Funding Information:
The BESIII collaboration thanks the staff of BEPCII and the IHEP computing center for their strong support. The authors thank Prof. Ru-Min Wang for helpful discussions. This work is supported in part by National Key R&D Program of China under Contracts No. 2020YFA0406300, No. 2020YFA0406400; National Natural Science Foundation of China (NSFC) under Contracts No. 11805037, No. 11635010, No. 11735014, No. 11835012, No. 11935015, No. 11935016, No. 11935018, No. 11961141012, No. 12022510, No. 12025502, No. 12035009, No. 12035013, No. 12061131003, No. 12192260, No. 12192261, No. 12192262, No. 12192263, No. 12192264, No. 12192265; No. 12165022; 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. U1832121, No. U1832207; CAS Key Research Program of Frontier Sciences under Contracts No. QYZDJ-SSW-SLH003, No. QYZDJ-SSW-SLH040; 100 Talents Program of CAS; The Institute of Nuclear and Particle Physics (INPAC) and Shanghai Key Laboratory for Particle Physics and Cosmology; Yunnan Fundamental Research Project under Contract No. 202301AT070162; ERC under Contract No. 758462; European Union’s Horizon 2020 research and innovation programme under Marie Sklodowska-Curie Grant Agreement No. 894790; German Research Foundation DFG under Contracts No. 443159800, No. 455635585, Collaborative Research Center CRC 1044, FOR5327, GRK 2149; Istituto Nazionale di Fisica Nucleare, Italy; Ministry of Development of Turkey under Contract No. DPT2006K-120470; National Science and Technology fund; National Science Research and Innovation Fund (NSRF) via the Program Management Unit for Human Resources & Institutional Development, Research and Innovation under Contract No. B16F640076; Olle Engkvist Foundation under Contract No. 200-0605; Polish National Science Centre under Contract No. 2019/35/O/ST2/02907; STFC (United Kingdom); Suranaree University of Technology (SUT), Thailand Science Research and Innovation (TSRI), and National Science Research and Innovation Fund (NSRF) under Contract No. 160355; The Royal Society, UK under Contracts No. DH140054, No. DH160214; The Swedish Research Council; U.S. Department of Energy under Contract No. DE-FG02-05ER41374.
Publisher Copyright:
© 2023 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.
PY - 2023/4/28
Y1 - 2023/4/28
N2 - The first direct measurement of the absolute branching fraction of ς+→Λe+νe is reported based on an e+e- annihilation sample of (10087±44)×106 J/ψ events collected with the BESIII detector at s=3.097 GeV. The branching fraction is determined to be B(ς+→Λe+νe)=[2.93±0.74(stat)±0.13(syst)]×10-5, which is the most precise measurement obtained in a single experiment to date and also the first result obtained at a collider experiment. Combining this result with the world average of B(ς-→Λe-ν¯e) and the lifetimes of ς±, the ratio, Γ(ς-→Λe-ν¯e)Γ(ς+→Λe+νe), is determined to be 1.06±0.28, which is within 1.8 standard deviations of the value expected in the absence of second-class currents.
AB - The first direct measurement of the absolute branching fraction of ς+→Λe+νe is reported based on an e+e- annihilation sample of (10087±44)×106 J/ψ events collected with the BESIII detector at s=3.097 GeV. The branching fraction is determined to be B(ς+→Λe+νe)=[2.93±0.74(stat)±0.13(syst)]×10-5, which is the most precise measurement obtained in a single experiment to date and also the first result obtained at a collider experiment. Combining this result with the world average of B(ς-→Λe-ν¯e) and the lifetimes of ς±, the ratio, Γ(ς-→Λe-ν¯e)Γ(ς+→Λe+νe), is determined to be 1.06±0.28, which is within 1.8 standard deviations of the value expected in the absence of second-class currents.
UR - http://www.scopus.com/inward/record.url?scp=85158844031&partnerID=8YFLogxK
U2 - 10.1103/PhysRevD.107.072010
DO - 10.1103/PhysRevD.107.072010
M3 - Article
SN - 2470-0010
VL - 107
JO - Physical Review D
JF - Physical Review D
IS - 7
M1 - 072010
ER -