The 3+1 scenario in MicroBooNE*

The discovery of an eV sterile neutrino would have a profound impact in particle physics, astrophysics and cosmology. Motivated by LSND results, and more recently by the Low-Energy Excess (LEE) observed in MiniBooNE, a new generation of experiments is looking for this new fermion. The latest results from MicroBooNE appear to disfavor the interpretation of the LEE just in terms of a new oscillation wavelength. This outcome is based on the non-observation of an electron-neutrino event excess in MicroBooNE compatible with LEE. Following the same procedure, we explore the impact that MiniBooNE's uncertainties on the LEE might have on the exclusion of the excess by MicroBooNE. Our results indicate that a large number of excess templates are still compatible with MiniBooNE results, but they cannot be excluded by MicroBooNE with a large significance. Finally, we perform a complete four-neutrino analysis of the data released, including the energy resolution and the covariance matrix. We explore the sensitivity in the Inclusive and the CCQE channels.  Although the present data allow to explore a fraction of the allowed parameter space, it is not completely covered, and therefore the scenario cannot be excluded.