Exploring Nonstandard Neutrino–Electron Interactions due to a New Light Spin-1 Boson

It is possible that nonstandard interactions of neutrinos arise from a new spin-1 particle with mass of tens of GeV or lower. Various existing data on neutrino-electron scattering and single-photon production in electron–positron collisions can impose considerable and complementary constraints on its couplings to the neutrinos and electron. If the new boson is sufficiently light, the constraints may significantly depend on its width as well as mass.