Activating the 4th Neutrino of the 3+1 Scheme

Understand

Non-Standard Interactions (NSI) of neutrinos with matter has received renewed interest in recent years.

• In particular, it has been shown that NSI can reconcile the $3+1$ solution with IceCube atmospheric data with $E_\nu >500$ GeV, provided that the effective coupling of NSI is large, e.g.
• $\sim 6 G_F$.
• The main goal of the present paper is to show that contrary to intuition, it is possible to build viable models with large NSI by invoking a new $U(1)$ gauge symmetry with gauge boson of mass $\sim 10$ eV.