Bonn 2010 – scientific programme
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T: Fachverband Teilchenphysik
T 21: Neutrinophysik (Theorie) I
T 21.6: Talk
Monday, March 15, 2010, 18:00–18:15, HG XV
Deviations from TBM in A4 neutrino mass models — •James Barry1, Werner Rodejohann1, and Steven Karataglidis2 — 1Max-Planck-Institut für Kernphysik, Heidelberg, Germany — 2Rhodes University, Grahamstown, South Africa
The addition of an A4 family symmetry and extended Higgs sector to the Standard Model can generate the tri-bimaximal mixing (TBM) pattern, assuming the correct vacuum expectation value (VEV) alignment of the Higgs scalars. Deviating this alignment affects the model predictions for the neutrino oscillation and neutrino mass observables.
Models with different A4 particle assignments have been analysed for deviations from TBM, by perturbing the VEV alignments, diagonalising the resulting neutrino and charged lepton mass matrices, and extracting the observables.
The models have been tested for any degree of fine tuning of the parameters that define the mass matrices. The effect of perturbations on the mixing angle observables, in particular sin2θ13 and sin2θ23 is studied, as well as the effect on the Jarlskog invariant, JCP. Investigations of the ⟨ mee ⟩ − ∑mν parameter space allow for comparison with current data from neutrinoless double beta decay experiments and cosmology, and can lead to the possible exclusion of a particular model by constraints from future data.