Constraining active-sterile neutrino transition magnetic moments at DUNE near and far detectors

We consider the sensitivity of DUNE experiment to a heavy neutral lepton, HNL (also known as sterile neutrino) in mass range from few MeV GeV, interacting with Standard Model via transition magnetic moment active neutrinos, so-called dipole portal. The is produced upscattering and subsequent decay inside detector provides single-photon signal. show that tau-neutrino portal can be efficiently probed at far detector, using flux generated by neutrino oscillations, while near better electron- muon-neutrino will able explore large regions currently unconstrained parameter space has comparable other planned dedicated experiments, such SHiP. also comment briefly on pure mixing tau detector.