Neutrino tridents at DUNE

Abstract

The DUNE near detector will collect an unprecedented large number of neutrino interactions, allowing the precise measurement of rare processes such as neutrino trident production, i.e., the generation of a lepton-antilepton pair through the scattering of a neutrino off a heavy nucleus. The event rate of this process is a powerful probe to a well-motivated parameter space of new physics beyond the Standard Model. In this paper, we perform a detailed study of the sensitivity of the DUNE near detector to neutrino tridents. We provide predictions for the Standard Model cross sections and corresponding event rates at the near detector for the νμ→νμμ+μ-, νμ→νμe+e- A nd νμ→νee+μ-trident interactions (and the corresponding antineutrino modes), discussing their uncertainties. We analyze all relevant backgrounds, utilize a Geant4-based simulation of the DUNE-near detector liquid argon TPC (the official DUNE simulation at the time of writing this paper), and identify a set of selection cuts that would allow the DUNE near detector to measure the νμ→νμμ+μ-cross section with a ∼40% accuracy after running in neutrino and anti-neutrino modes for ∼3 years each. We show that this measurement would be highly sensitive to new physics, and, in particular, we find that the parameter space of models with gauged Lμ-Lτ that can explain the (g-2)μ anomaly could be covered with large significance. As a by-product, a new Monte Carlo tool to generate neutrino trident events is made publicly available.