Symmetry, Hierarchy, and an Alternative Paradigm for Analyzing Neutrino Oscillations
Cogswell, Bernadette Kafwimbi
:
2014-10-28
Abstract
We conducted an updated global analysis of neutrino oscillation data using alternative
bounds on the mixing angle theta-13 to determine the best fit mixing angles theta-13 and theta-23, the mass-
squared difference ∆m_32^2, and the preferred neutrino mass hierarchy. Data analyzed included all
the MINOS data, all the T2K data, Daya Bay, RENO, and the constraint from the Super-
Kamiokande atmospheric data for the mixing angle theta-23. Using these alternative bounds
highlights the presence of four solutions in the case of CP-conservation, one for each neutrino
mass hierarchy and sign of theta-13 combination. The global data is sensitive enough to linear in theta-13
effects and symmetry-breaking matter effects in the long baseline accelerator data to distinguish
between these four solutions. We find that the best fit solution is the normal hierarchy, positive
theta-13 solution, which has a 58.6% probability of being the true solution. Using a full, exact, three-
neutrino equation with a constant density matter profile and marginalizing over unwanted
parameters, we find the best fit mixing parameters for this solution to be theta-13 = 0.158 - 0.012 + 0.014 rads,
theta-23 = 0.868 -0.178 +0.039 rads, and ∆m_32^2 = 2.42 -0.08 +0.08 ~ 10^-3 eV^2.