Speaker
Description
The intense meson fluxes produced in conventional neutrino beamlines provide a rich test bed for probing long-lived particles beyond the Standard Model. MicroBooNE, a liquid argon time projection chamber at Fermilab, is uniquely positioned for such searches, operating both off-axis to the Main Injector Neutrino (NuMI) beamline and on-axis to the Booster Neutrino Beam (BNB).
In this talk, I will present two searches that exploit decays of the NuMI kaon flux to constrain dark-sector models. First, I will describe our recent search for higgs portal scalars decaying to electron–positron pairs, which set the strongest experimental limits for scalar masses between 110 and 155 MeV. I will then discuss our most recent search for heavy neutral leptons, targeting both electron–positron and neutral pion visible final states. This analysis has already achieved world-leading constraints on sterile neutrino masses between 35 and 175 MeV, but I will go further by outlining ongoing efforts to maximise sensitivity using the full MicroBooNE dataset and improved analysis techniques.