Longer-lived mediators from charged mesons and photons at neutrino experiments Bhaskar Dutta,*Aparajitha Karthikeyan ,?and Doojin Kim? Department of Physics and Astronomy, Texas A&M University, College Station, Texas 77845, USA (Received 14 September 2023; accepted 18 March 2024; published 16 April 2024) Since many of the dark-sector particles interact with Standard Model (SM) particles in multiple ways, they can appear in experimental facilities where SM particles appear in abundance. In this s...