Neutrino-induced deuteron disintegration experiment

TL;DR

This paper reports measurements of neutrino-induced deuteron disintegration cross sections, confirming theoretical predictions and providing a precise measurement of the isovector-axial vector coupling constant in the hadronic weak interaction.

Contribution

The study provides the first precise experimental measurements of neutrino-induced deuteron disintegration cross sections and tests the Standard Model prediction for the axial coupling constant.

Findings

Measured NCD cross section: 6.08 +/- 0.77 x 10^(-45) cm^2

Measured CCD cross section: 9.83 +/- 2.04 x 10^(-45) cm^2

Measured axial coupling constant beta^2: 1.01 +/- 0.16

Abstract

Cross sections for the disintegration of the deuteron via neutral-current (NCD) and charged-current (CCD) interactions with reactor antineutrinos are measured to be 6.08 +/- 0.77 x 10^(-45) cm-sq and 9.83 +/- 2.04 x 10^(-45) cm-sq per neutrino, respectively, in excellent agreement with current calculations. Since the experimental NCD value depends upon the CCD value, if we use the theoretical value for the CCD reaction, we obtain the improved value of 5.98 +/- 0.54 x 10^(-45) for the NCD cross section. The neutral-current reaction allows a unique measurement of the isovector-axial vector coupling constant in the hadronic weak interaction (beta). In the standard model, this constant is predicted to be exactly 1, independent of the Weinberg angle. We measure a value of beta^2 = 1.01 +/- 0.16. Using the above improved value for the NCD cross section, beta^2 becomes 0.99 +/- 0.10.