A light scalar explanation of (g − 2)μ and the KOTO anomaly

• DOI: 10.1007/jhep04(2020)197
• Publication Date: 2020-04-30T21:03:03Z
• Authors: Jia Liu; Navin McGinnis; Carlos E.M. Wagner; Xiao-Ping Wang
• Keywords: High Energy Physics - Phenomenology; High Energy Physics - Experiment (hep-ex); Higgs Physics; High Energy Physics - Phenomenology (hep-ph); Nuclear and particle physics. Atomic energy. Radioactivity; Beyond Standard Model; 0103 physical sciences; FOS: Physical sciences; QC770-798; 01 natural sciences; High Energy Physics - Experiment

The KOTO experiment has recently performed a search for neutral Kaons decaying into pions and pair of neutrinos. Three events were observed in the signal region, with an expected background about 0.05. Since no clear systematic errors have been found, excess decay KL→ π0ν $$ \overline{v} is quite intriguing. One possibility to explain this anomaly would be presence scalar 𝜙 mass order pion inducing decays π0𝜙 which mimic signal. A coupling muons Standard Model Higgs could also muon anomalous magnetic moment (g − 2)μ. We built on these facts show that light singlet couplings leptons quarks as ones induced by mixing states two doublet models may lead explanation both anomalies. More specifically, we case so-called type-X couple different doublets, masses are range between 40 70 MeV. Due relatively large required fit 2)μ, lifetime accidentally falls sub-nanosecond essential evade severe proton beam dump experiments astrophysical constraints, though it becomes sensitive constraints from electron experiments. additional phenomenological properties model discussed.