Studies of quantum-mechanical coherency effects in neutrino-nucleus elastic scattering

Abstract

Neutrino-nucleus elastic scattering (νAel) provides a unique laboratory to study the quantum-mechanical (QM) coherency effects in electroweak interactions. The deviations of the cross sections from those of completely coherent systems can be quantitatively characterized through a coherency parameter α(q2). The relations between α and the underlying nuclear physics in terms of nuclear form factors are derived. The dependence of cross section on α(q2) for the various neutrino sources is presented. The α(q2) values are evaluated from the measured data of the COHERENT CsI and Ar experiments. Complete coherency and decoherency conditions are excluded by the CsI data with p=0.004 at q2=3.1×103 MeV2 and p=0.016 at q2=2.3×103 MeV2, respectively, verifying that both QM superpositions and nuclear many-body effects contribute to νAel interactions. © 2021 authors. Published by the American Physical Society.