Up-scattering production of a sterile fermion at DUNE: complementarity with spallation source and direct detection experiments

This paper investigates the potential production of a MeV-scale sterile fermion through neutrino up-scattering on nuclei and atomic electrons at various facilities. A phenomenological model is used, adding a new fermion to the Standard Model and considering all possible Lorentz-invariant non-derivative interactions. The authors explore DUNE's sensitivity, simulating elastic neutrino-electron scattering events in the near detector using standard and tau-optimized beams. Constraints on couplings, fermion masses, and mediator masses are inferred from solar neutrino events in XENONnT and LZ, and from coherent elastic neutrino-nucleus scattering data from COHERENT. The impact of sterile fermion decay within the detector is also assessed. The study highlights the complementarity of these facilities in exploring different regions of the parameter space.

Pablo M. Candela, Valentina De Romeri, Pantelis Melas, Dimitrios K. Papoulias, Niki Saoulidou