Events at Physics |
This is the first application of SDA to solar neutrinos using real data - measurements of Boron-8 solar neutrino flavor recorded by the Borexino and Sudbury Neutrino Observation (SNO) experiments were used to constrain neutrino flavor towards the edge of the sun. In the first case, we used this data as a test of the technique. We performed this optimization procedure with multiple energy bins matching the observations from the Borexino and SNO experiments separately. With both sets of measurements, we found that incorporating MSW resonance into the flavor evolution dynamics produces results consistent with the observations.
In the second case, we introduced parameter estimation by allowing the procedure to vary the matter potential inside the sun. As a test of adiabaticity, we used two different monotonically decreasing models of the matter potential as a function of radius. For each model, the potential was held fixed at the edge of our zone of inference to match the standard solar model, while the value at the core of the sun was used as a varying parameter. For both models, we found that a core potential between 0.025 and 0.030 per kilometer produces results most consistent with observed neutrino fluxes.