  We investigate the possibility of using neutrino trident production to probe
leptophilic charged scalars at future high intensity neutrino experiments. We
show that under specific assumptions, this production process can provide
competitive sensitivity for generic charged scalars as compared to common
existing bounds. We also investigate how the recently proposed mixed-flavour
production - where the two oppositely charged leptons in the final state need
not be muon flavoured - can give a 20-50% increase in sensitivity for certain
configurations of new physics couplings as compared to traditional trident
modes. We then categorize all renormalizable leptophilic scalar extensions
based on their representation under $SU(2)\times U(1)$, and discuss the Higgs
triplet and Zee-Babu models as explicit UV realizations. We find that the
inclusion of additional doubly charged scalars and the need to reproduce
neutrino masses make trident production uncompetitive with current bounds for
these specific UV completions. Our work represents the first application of
neutrino trident production to study charged scalars, and of mixed-flavour
final states to study physics beyond the Standard Model.
