  We investigate the possible production of a MeV-scale sterile fermion through
the up-scattering of neutrinos on nuclei and atomic electrons at different
facilities. We consider a phenomenological model that adds a new fermion to the
particle content of the Standard Model and we allow for all possible
Lorentz-invariant non-derivative interactions (scalar, pseudoscalar, vector,
axial-vector and tensor) of neutrinos with electrons and first-generation
quarks. We first explore the sensitivity of the DUNE experiment to this
scenario, by simulating elastic neutrino-electron scattering events in the near
detector. We consider both options of a standard and a tau-optimized neutrino
beams, and investigate the impact of a mobile detector that can be moved
off-axis with respect to the beam. Next, we infer constraints on the typical
coupling, new fermion and mediator masses from elastic neutrino-electron
scattering events induced by solar neutrinos in two current dark matter direct
detection experiments, XENONnT and LZ. Under the assumption that the new
mediators couple also to first-generation quarks, we further set constraints on
the up-scattering production of the sterile fermion using coherent elastic
neutrino-nucleus scattering data from the COHERENT experiment. Moreover, we set
additional constraints assuming that the sterile fermion may decay within the
detector. We finally compare our results and discuss how these facilities are
sensitive to different regions of the relevant parameter space due to
kinematics arguments and can hence provide complementary information on the
up-scattering production of a sterile fermion.
