New bounds on axion-like particles from MicroBooNE

Neutrino experiments lie at the edge of intensity frontier and therefore can be exploited to search for new light particles weakly coupled visible sector. In this work we derive constraints on axion-like (ALPs) using data from MicroBooNE experiment, a $e^+ e^-$ pairs pointing in direction NuMI absorber. particular, consider addition higher-dimensional effective operators coupling ALP electroweak gauge bosons. These would induce $K\to \pi a$ kaon decay rest absorber, as well decays into leptons or photons. We discuss detail compare various results obtained width $K\rightarrow previous literature. For operator involving Higgs, already sets competitive bounds (comparable those NA62) masses between 100 200 MeV. also compute expected sensitivities full dataset recorded MicroBooNE. Our show that $a\to\gamma\gamma$ signal may able improve over current beam-dump $W$.