Measurement of electron-neutrino electron elastic scattering

TL;DR

This paper reports a precise measurement of the electron-neutrino electron elastic scattering cross section, confirming the standard model predictions and setting limits on neutrino flavor-changing processes and magnetic moments.

Contribution

First measurement of nu_e e- elastic scattering cross section using a mu+ decay-at-rest neutrino beam, validating standard model predictions and constraining new physics.

Findings

Measured cross section agrees with standard model

Interference parameter matches theoretical expectations

Set upper limit on muon-neutrino magnetic moment

Abstract

The cross section for the elastic scattering reaction nu_e+e- -> nu_e+e- was measured by the Liquid Scintillator Neutrino Detector using a mu+ decay-at-rest nu_e beam at the Los Alamos Neutron Science Center. The standard model of electroweak physics predicts a large destructive interference between the charge current and neutral current channels for this reaction. The measured cross section, sigma_{nu_e e-}=[10.1 +- 1.1(stat.) +- 1.0(syst.)]x E_{nu_e} (MeV) x 10^{-45} cm^2, agrees well with standard model expectations. The measured value of the interference parameter, I=-1.01 +- 0.13(stat.) +- 0.12(syst.), is in good agreement with the standard model expectation of I^{SM}=-1.09. Limits are placed on neutrino flavor-changing neutral currents. An upper limit on the muon-neutrino magnetic moment of 6.8 x 10^{-10} mu_{Bohr} is obtained using the nu_mu and \bar{nu}_mu fluxes from pi+ and mu+ decay.