Inference finds consistency between a neutrino flavor evolution model and Earth-based solar neutrino measurements

Abstract

We continue examining statistical data assimilation, an inference methodology, to infer solutions to neutrino flavor evolution, for the first time using real---rather than simulated---data. The model represents neutrinos streaming from the Sun's center and undergoing a Mikheyev-Smirnov-Wolfenstein resonance in flavor space, due to the radially varying electron number density. The model neutrino energies are chosen to correspond to experimental bins in the Sudbury Neutrino Observatory and Borexino experiments, which measure electron-flavor survival probability at Earth. The procedure successfully finds consistency between the observed fluxes and the model, if the Mikheyev-Smirnov-Wolfenstein resonance---that is, flavor evolution due to solar electrons---is included in the dynamical equations representing the model.