@misc{10481/78953,
year = {2022},
month = {11},
url = {https://hdl.handle.net/10481/78953},
abstract = {We present a search for long-lived Higgs portal scalars (HPS) and heavy neutral leptons (HNL) decaying in the MicroBooNE liquid-argon time projection chamber. The measurement is performed using data collected synchronously with the neutrino beam from Fermilab’s Main Injector with a total exposure corresponding to 7.01×1020 protons on target. We set upper limits at the 90% confidence level on the mixing parameter |Uμ4|2 ranging from |Uμ4|2<12.9×10−8 for Majorana HNLs with a mass of mHNL=246  MeV to |Uμ4|2<0.92×10−8 for mHNL=385  MeV, assuming |Ue4|2=|Uτ4|2=0 and HNL decays into μ±π∓ pairs. These limits on |Uμ4|2 represent an order of magnitude improvement in sensitivity compared to the previous MicroBooNE result. We also constrain the scalar-Higgs mixing angle θ by searching for HPS decays into μ+μ− final states, excluding a contour in the parameter space with lower bounds of θ2<31.3×10−9 for mHPS=212  GeV and θ2<1.09×10−9 for mHPS=275  GeV. These are the first constraints on the scalar-Higgs mixing angle θ from a dedicated experimental search in this mass range.},
organization = {European Union’s Horizon 2020 Marie Skłodowska-Curie Actions},
organization = {Fermi Research Alliance, LLC
	DE-AC02-07CH11359},
organization = {High Energy Physics and Nuclear Physics},
organization = {United Kingdom Research and Innovation},
organization = {National Science Foundation},
organization = {U.S. Department of Energy},
organization = {Office of Science},
organization = {Science and Technology Facilities Council},
organization = {Royal Society},
organization = {Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung},
publisher = {American Physical Society},
title = {Search for long-lived heavy neutral leptons and Higgs portal scalars decaying in the MicroBooNE detector},
doi = {10.1103/PhysRevD.106.092006},
author = {Abratenko, P. and García Gámez, Diego and Microboone Collaboration},
}