DUNE sensitivities to the mixing between sterile and tau neutrinos ; Journal of High Energy Physics

Abstract

Light sterile neutrinos can be probed in a number of ways, including electroweak decays, cosmology and neutrino oscillation experiments. At long-baseline experiments, the neutral-current data is directly sensitive to the presence of light sterile neutrinos: once the active neutrinos have oscillated into a sterile state, a depletion in the neutral-current data sample is expected since they do not interact with the Z boson. This channel offers a direct avenue to probe the mixing between a sterile neutrino and the tau neutrino, which is currently only weakly constrained by current data from SuperK, IceCube and NOvA, however, these constrains will continue to improve as more data is collected by these experiments. In this work, we study the potential of the DUNE experiment to constrain the mixing angle which parametrizes this mixing, theta(34), through the observation of neutral-current events at the far detector. We find that DUNE will be able to improve significantly over current constraints thanks to its large statistics and excellent discrimination between neutral- and charged-current events. ; Sao Paulo Research Foundation (FAPESP) [2014/19164-6, 2017/01749-6] ; U.S. Department Of Energy [DE-SC0013632, DE-SC0009973] ; European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant [674896] ; U.S. Department of Energy, Office of Science, Office of High Energy Physics [DE-AC02-07CH11359] ; We warmly thank Michel Sorel for providing us with the smearing matrices needed to simulate the liquid Argon detector reconstruction for neutral-current events. PC also thanks Enrique Fernandez-Martinez for useful discussions. DVF is thankful for the support of Sao Paulo Research Foundation (FAPESP) funding Grant No. 2014/19164-6 and 2017/01749-6., and also for the URA fellowship that allowed him to visit the theory department at Fermilab where this project started. DVF was also supported by the U.S. Department Of Energy under contracts DE-SC0013632 and DE-SC0009973. This work has received partial support from the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No. 674896. This manuscript has been authored by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the U.S. Department of Energy, Office of Science, Office of High Energy Physics. The United States Government retains and the publisher, by accepting the article for publication, acknowledges that the United States Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce the published form of this manuscript, or allow others to do so, for United States Government purposes.