par Chu, Xiaoyong 
;Dhen, Mikaël ;Hambye, Thomas
Référence The Journal of high energy physics, 2011, 11, 106
Publication Publié, 2011
;Dhen, Mikaël ;Hambye, Thomas Référence The Journal of high energy physics, 2011, 11, 106
Publication Publié, 2011
Article révisé par les pairs
| Résumé : | The recent T2K and MINOS indications for a "large" θ13 neutrino mixing angle can be accommodated in principle by an infinite number of Yukawa avour structures in the seesaw model. Without considering any explicit avour symmetry, there is an instructive exercise one can do: to determine the simplest avour structures which can account for the data with a minimum number of parameters, simply assuming these parameters to be uncorrelated. This approach points towards a limited number of simple structures which show the minimum complexity a neutrino mass model must generally involve to account for the data. These basic structures essentially lead to only 4 relations between the neutrino observables. We emphasize that 2 of these relations, j sin θ13I = tan θ231-tan θ 12/cos δ 1+tan θ12 and I sin θ13I = sin θ12Rθ1/4, with R ≡ Δm221=/Δm232, have several distinctive properties. First, they hold not only with a minimum number of parameters, but also for complete classes of more general models. Second, any value of θ13 within the T2K and MINOS ranges can be obtained from these relations by taking into account small perturbations. Third, they turn out to be the pivot relations of models with approximate conservation of lepton number, which allow the seesaw interactions to induce observable avour violating processes, such as μ → εγ and τ → μγ. Finally, in specific cases of this kind, these structures have the rather unique property to allow a full reconstruction of the seesaw Lagrangian from low energy data. © SISSA 2011. |
