Explaining the MiniBooNE anomalous excess via a leptophilic ALP-sterile neutrino coupling

Recently, the MiniBooNE experiment at Fermilab has updated the results with increased data and reported an excess of electronlike events () in the neutrino operation mode. In this paper, we propose a scenario to account for the excess where a Dirac-type sterile neutrino, produced by a charged kaon decay through the neutrino mixing, decays into a leptophilic axionlike particle () and a muon neutrino. The electron-positron pairs produced from the decays can be interpreted as electronlike events provided that their opening angle is sufficiently small. In our framework, we consider the with a mass and an inverse decay constant , allowed by the astrophysical and experimental constraints. Then, after integrating the predicted angular or visible energy spectra of the to obtain the total excess event number, we find that our scenario with sterile neutrino masses within () and neutrino mixing parameters between () can explain the MiniBooNE data.