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 ν µ → ν µ µ + µ − , ν µ → ν µ e + e − and ν µ → ν e e + 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 ν µ → ν µ µ + 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 L µ − L τ that can explain the (g − 2) µ anomaly could be covered with large significance. As a byproduct, a new Monte Carlo tool to generate neutrino trident events is made publicly available. *

Searches for decays of new particles in the DUNE Multi-Purpose near Detector

“…However, as discussed in Section 4, the expected number of neutrino-related e + e − background events is very small for ten years of data collection. ¶ In the DUNE MPD, roughly 20 e + e − -trident events are also expected [70,71]. This rate, and the kinematics of such events, may be predicted in a data-driven way by using the sample of ∼ 1000 events expected in the liquid argon TPC.…”

“…anomaly [80,83,84,92,93]. This solution requires gµτ > 10 −4 for MV > 1 MeV, and will be probed by neutrino trident interactions in the DUNE LArTPC Near Detector [71,94]. exists.…”

“…Refs. [70,71] estimate O (20) neutrino trident e + e − events in the MPD (we obtain this by scaling their LArTPC projections to the mass of the HPTPC) in ten years. Their kinematics should be different from our signature (in terms of invariant mass, direction, etc.)…”

Complete vectorlike fourth family with U(1)′ : A global analysis

“…The Z contributes to muon-neutrino induced muon pair production off a nucleus ν µ N → ν µ µ + µ − N , the so-called neutrino trident process [6,[107][108][109][110][111]. The cross section for this process at the CCFR experiment is estimated as [111] (see also [112] for a complete SM computation)…”

“…and we have used s 2 W = 0.23129 specifically for this process as in Ref. [111]. This constraint is relevant only for light Z 's and becomes unimportant for m Z 200 GeV.…”