High-energy (HE; ~100 GeV to 100 PeV) and ultrahigh-energy (UHE; >~ 100 PeV) neutrinos are essential for advancing both particle physics and astrophysics, offering significant opportunities to study neutrino interactions and test the Standard Model and beyond. On the other hand, neutrino interactions are the cornerstone of all neutrino measurements, as neutrinos are always detected via particles from their interactions. Studying neutrino interactions also reveals new event classes (e.g., dimuons), offering novel measurement opportunities. Neutrino interaction theory is both interesting and challenging: although neutrinos only participate in gravitational and weak interactions, neutrino interaction studies relevant to neutrino experiments also significantly involve strong interactions and quantum electrodynamics. For sub-TeV–EeV neutrinos, while the dominant interaction, deep-inelastic scattering (DIS), is well understood, the increasing data from current and future experiments demands studying subdominant interactions, which remain poorly understood.
In this talk, I will talk about the studies of the sub-TeV--EeV neutrino interactions and detection, including W-boson and trident production (1910.08090, 1910.10720, 2305.10497, 2406.16803), dimuon (2110.02974), and final state radiation (2403.07984; a QED radiative correction as large as 25% while completely overlooked by current experiments).