PHYSICAL REVIEW D, vol.103, no.9, 2021 (SCI-Expanded)
Neutrino-nucleus elastic scattering (nu A(el)) 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 alpha(q(2)). The relations between a and the underlying nuclear physics in terms of nuclear form factors are derived. The dependence of cross section on alpha(q(2)) for the various neutrino sources is presented. The alpha(q(2)) 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 q(2) = 3.1 x 10(3) MeV2 and p = 0.016 at q(2) = 2.3 x 10(3) MeV2, respectively, verifying that both QM superpositions and nuclear many-body effects contribute to.Ael interactions.