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arXiv · 2610.07773

Search for rare charm decays at BESIII

Xiaokang Li·for the BESIII Collaboration
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Abstract

The BESIII experiment searches for rare and symmetry-violating decays with the largest charmonium and threshold open-charm data samples. This contribution reviews recent searches for charmonium weak decays, charm flavour-changing neutral currents, charged-lepton flavour violation, and Bose-symmetry violation. The weak-decay searches have improved several branching-fraction limits, while studies of rare charm-meson and charmonium decays probe flavour-changing neutral currents. Searches for charged-lepton flavour violation set limits in vector and pseudoscalar meson decays and constrain effective interactions. No significant signals are found in any of these searches. The neutral-kaon limits fall below the expectations of a proposed locality scenario, and the $J/ψ$ limit approaches the scale predicted for Standard Model CP violation.

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Xiaokang Li, for the BESIII Collaboration. 2026-10-06. Search for rare charm decays at BESIII. https://arxiv.org/abs/2610.07773

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