Non-standard neutrino interactions in K^{+}\toπ^{+}ν\barν and D^{+}\toπ^{+}ν\barν decays

Abstract

We study the contributions of the non-standard neutrino interactions (NSIs) to the rare meson decays of $K^{+}\to π^{+} ν\barν$ and $D^{+}\to π^{+} ν\barν$. We show that both decays could provide strong constraints on the free parameters in the NSIs. We point out that the branching ratio of $D^{+}\to π^{+} ν\barν$ could be at the level of $10^{-8}$.