Speaker
Description
Neutral mesons such as pi0 and eta have played a role of an important source of dark sector particles including dark matter in the beam-dump type and neutrino experiments. We point out that charged mesons are another important but overlooked source of dark sector particles especially in the beam-focused neutrino experiments. The idea is that a charged meson decays to a charged lepton, a neutrino counterpart, and a dark-sector mediator. As this three-body decay is helicity-unsuppressed unlike the corresponding two-body decay and the charged mesons are focused by the magnetic horn, we expect an enhanced dark-sector signal flux. We discuss two examples: a dark-matter solution to the MiniBooNE low energy excess and the light dark matter search at SBND.
