Detection of v̄ _e — e Scattering

Abstract

The reaction ν̄e + e^- → ν̄e + e^- has been observed using a 15.9 kg plastic scintillation target in a composite plastic-Nal-liquid detector exposed to a ν̄e flux of 2.2 × 10¹³ cm^-2s^-1 from an 1800 MW fission reactor. Tests rule out a reactor-associated signal produced by inverse β-decay, neutrons, or gamma rays. The measured cross section is consistent with both, the old V — A theory and the Weinberg-Salam model with a mixing parameter sin² θ _w = 0.29 ± 0.05.

Sponsored by the U.S. Energy Research and Development Administration

Edited version of the tape record, supplemented by data from the authors’ publication in Phys. Rev. Letters 37, 315 (1976).