2022/08/01 by C. Lin, Lin, Chieh
Physics and Astronomy · #Dark Matter and Cosmic Phenomena #FOS: Physical sciences #High Energy Physics - Experiment (hep-ex) #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions
paper · pdf · doi:10.48550/arxiv.2208.01144
openalex publication_date 2022/08/01 · openalex created_date 2022/10/01 · openalex updated_date 2026/07/28
The experimental status of the K → πνν search is presented. The K → πνν decay is sensitive to New Physics because it is theoretically pristine and highly suppressed. The KL0 → π0 νν search is performed by the KOTO experiment and a branching fraction limit of B(KL0 → π0 νν) < 3.0 × 10-9 (90% confidence level) was set. This limit is O(100) times larger than the Standard Model prediction. The K+ → π+ νν search is performed by the NA62 experiment and B(K+ → π+ νν) = (10.6 +4.0-3.5 |stat.) ± 0.9syst.) × 10-11 (68% confidence level) was set. This shows an agreement with the Standard Model. Both measurements can also be used to search for the dark particle X via the K → πX decay. A projection of the K → πνν search in the future is also given.