Constraints on nonstandard neutrino interactions and unparticle physics withν¯e−e−scattering at the Kuo-Sheng nuclear power reactor

Neutrino-electron scatterings are purely leptonic processes with robust standard model (SM) predictions. Their measurements can therefore provide constraints to physics beyond SM. The ${\overline{\ensuremath{\nu}}}_{\mathrm{e}}\ensuremath{-}\mathrm{e}$ data taken at the Kuo-Sheng Reactor Neutrino Laboratory were used to probe two scenarios: nonstandard neutrino interactions (NSI) and unparticle physics. New constraints were placed on the NSI parameters $({\ensuremath{\epsilon}}_{\mathrm{ee}}^{\mathrm{eL}},{\ensuremath{\epsilon}}_{\mathrm{ee}}^{\mathrm{eR}})$, $({\ensuremath{\epsilon}}_{\mathrm{e}\ensuremath{\mu}}^{\mathrm{eL}},{\ensuremath{\epsilon}}_{\mathrm{e}\ensuremath{\mu}}^{\mathrm{eR}})$, and $({\ensuremath{\epsilon}}_{\mathrm{e}\ensuremath{\tau}}^{\mathrm{eL}},{\ensuremath{\epsilon}}_{\mathrm{e}\ensuremath{\tau}}^{\mathrm{eR}})$ for the nonuniversal and flavor-changing channels, respectively, as well as to the coupling constants for scalar (${\ensuremath{\lambda}}_{0}$) and vector (${\ensuremath{\lambda}}_{1}$) unparticles to the neutrinos and electrons.