Search for the lepton number violation decay ϕ → π + π + e − e − via J / ψ → ϕη * * The BESIII Collaboration appreciates the staff of BEPCII and the IHEP Computing Center for their strong support. This work is supported in part by the National Key R&D Program of China (2020YFA0406300, 2020YFA0406400); National Natural Science Foundation of China (NSFC) (12035009, 11635010, 11735014, 11835012, 11935015, 11935016, 11935018, 11961141012, 12025502, 12035013, 12061131003, 12192260, 12192261, 12192262, 12192263, 12192264, 12192265, 12221005, 12225509, 12235017); 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 (U1832207); CAS Key Research Program of Frontier Sciences (QYZDJ-SSW-SLH003, 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; the European Union's Horizon 2020 research and innovation program under the Marie Sklodowska-Curie grant agreement (894790); the German Research Foundation DFG (455635585), the Collaborative Research Center CRC 1044, FOR5327, GRK 2149; Istituto Nazionale di Fisica Nucleare, Italy; Knut and Alice Wallenberg Foundation (2021.0174, 2021.0299); Ministry of Development of Turkey (DPT2006K-120470); National Research Foundation of Korea (NRF-2022R1A2C1092335); National Science and Technology Fund of Mongolia; National Science Research and Innovation Fund (NSRF) via the Program Management Unit for Human Resources & Institutional Development, Research and Innovation of Thailand (B16F640076); Polish National Science Centre (2019/35/O/ST2/02907); Swedish Research Council (2019.04595); the Swedish Foundation for International Cooperation in Research and Higher Education (CH2018-7756); and the U. S. Department of Energy (DE-FG02-05ER41374)

Journal article

Using an electron-positron collision data sample corresponding to events collected using the BESIII detector at the BEPCII collider, we firstly search for the lepton number violation decay via . No obviously signals are found. The upper limit on the branching fraction of is set to be at the 90% confidence level.

Authors: Ablikim, M; Achasov, MN; Adlarson, P; Afedulidis, O; Ai, XC

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Chinese Physical Society and the Institute of High Energy Physics of the Chinese Academy of Sciences and the Institute of Modern Physics of the Chinese Academy of Sciences and IOP Publishing Ltd
• Journal: Chinese Physics C
• Volume: 49
• Issue: 4
• Article number: 043001
• Publication date: 2025-04-01
• DOI: 10.1088/1674-1137/ada350
• ISSN: 1674-1137
• Language: English
• Keywords: matter anti-matter asymmetry; neutrinoless double beta decay; Lepton number violation