2024/11/06 by Maël Cavan-Piton, Diego Guadagnoli, Cavan-Piton, Mael +7 · 2 citations
Physics and Astronomy · #Dark Matter and Cosmic Phenomena #FOS: Physical sciences #High Energy Physics - Experiment (hep-ex) #High Energy Physics - Phenomenology (hep-ph) #Particle Detector Development and Performance #Particle physics theoretical and experimental studies
paper · pdf · doi:10.48550/arxiv.2411.04170
openalex publication_date 2024/11/06 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Two-body decays like K → πa rank among the most constraining collider probes for new, low-mass, feebly interacting pseudoscalar particles a. We explore an alternative class of kaon decay modes, specifically three-body decays to ππa or μμa. The former occur at tree level, while the latter is loop-suppressed yet accidentally finite. These modes specifically leverage the accurate tracking capabilities at LHCb. We present an estimation approach for the sensitivity achievable in future searches within these channels. Our argument uses the current uncertainty in leading irreducible backgrounds identified for each channel. Our findings suggest that dedicated searches could probe fa scales between 104 and 106 TeV, highlighting their strong potential. A direct comparison with actual searches, only available in the K+ → π+ π0 a channel, supports this conclusion. Finally, we show that, in these searches, reconstruction efficiency maps are such that large efficiencies are naturally aligned with regions of higher yields in Dalitz plots.