Probing Light Dark Particles in Neutrino Scattering Experiments

In this work we investigate the production of a dark fermionic particle $\chi$ in the neutrino scattering experiments. In the framework of effective field theory, such process can be induced by the effective four-fermion interactions involving neutrinos, the dark particle $\chi$ and standard model particles. In particular, we examine the constraints on the effective couplings from the neutrinos scattering off nuclei in the COHERENT and CONUS+ experiments as well as the prospects at the DUNE near detector from neutrino-electron scattering. It turns out the current COHERENT and CONUS+ constraints on the cutoff scales are less stringent than those from the existing Large Hadron Collider data. However, the DUNE near detector could probe the cutoff scales beyond the existing CHARM II and LEP limits up to roughly 1 TeV, for the dark particle mass up to roughly 50 MeV.