Search for sterile neutrino with light gauge interactions: recasting collider, beam-dump, and neutrino telescope searches.

We investigate features of the sterile neutrinos in the presence of a light gauge boson $X^\mu$ that couples to the neutrino sector. The novel bounds on the active-sterile neutrino mixings $| U_{\ell 4} |^2$, especially for tau flavor ($l = \tau$), from various collider and fixed target experiments are explored. Also, taking into account the additional decay channel of the sterile neutrino into a light gauge boson ($\nu_4 \to \nu_\ell e^+ e^-$), we explore and constrain a parameter space for low energy excess in neutrino oscillation experiments.