Coherency in Neutrino-Nucleus Elastic Scattering

Neutrino-nucleus elastic scattering provides a unique laboratory to study the quantum mechanical coherency effects in electroweak interactions, towards which several experimental programs are being actively pursued. We report results of our quantitative studies on the transitions towards decoherency. A parameter (alpha) is identified to describe the degree of coherency, and its variations with incoming neutrino energy, detector threshold, and target nucleus are studied. The ranges of alpha that can be probed with realistic neutrino experiments are derived, indicating complementarity between projects with different sources and targets. Uncertainties in nuclear physics and in alpha would constrain sensitivities in probing physics beyond the standard model. The maximum neutrino energies corresponding to alpha > 0.95 are derived.