Detection ofν¯e−eScattering

Abstract

The reaction ${\overline{\nu }}_e+e^{-}\to {\overline{\nu }}_e+e^{-}$ has been observed using a 15.9-kg plastic scintillation target in a composite plastic-NaI-liquid detector exposed to a ${\overline{\nu }}_e$ flux of 2.2×${10}^{13}$ ${\mathrm{cm}}^{-2\mathrm{}}$ ${\sec }^{-1\mathrm{}}$ from an 1800-MW fission reactor. Tests rule out a reactor-associated signal produced by inverse $\beta$ decay, neutrons, or gamma rays. The measured cross section is consistent with $V-A$ and the Weinberg model with parameter ${{sin}^2\theta }_{\mathrm{W}}=0.29\mathrm{}\pm 0.05$.