A light Z^prime for the R_K puzzle and nonstandard neutrino interactions

We show that the $R_K$ puzzle in LHCb data and the discrepancy in the anomalous magnetic moment of the muon can be simultaneously explained if a 10 MeV mass $Z^\prime$ boson couples to the muon but not the electron, and that clear evidence of the nonstandard matter interactions of neutrinos induced by this coupling may be found at DUNE.