Ponente
Ye-Ling Zhou
(IPPP, Durham University)
Descripción
Current neutrino oscillation data suggests specific flavour structures in lepton sector which can be explained by underlying flavour symmetries. In leptonic flavour models with discrete flavour symmetries, flavons play a key role to realise these structures. They gain vacuum expectation values which respect different residual symmetries in the charged lepton and neutrino sectors and result in special mixing structures after the breaking of the flavour symmetry. I will introduce a new approach to connect flavour mixing with cross couplings of different flavons. Depending on the coefficients in the flavon potential, different vacua preserving different residual symmetries can be identified and the tri-bimaximal (TBM) mixing are realised at leading order. Cross couplings of these flavons result in the breaking of the residual symmetries and corrections to TBM. These couplings provide new origins for the non-zero reactor angle and CP violation. Models in this approach can be achieved by introducing only a few degrees of freedom and can be more economical than those in the framework of extra dimension or supersymmetry. It also provides a new way, different from higher dimensional operators, to modify flavour mixing from its leading order results. Simplicity, as a great advantage of this approach, makes it possible for us to establish definite relations between mixing parameters and properties of flavons on one hand, and test the phenomenological property of flavons on the other hand. One aspect is to test the couplings of flavons and leptons. These couplings violate lepton flavours, resulting in both flavour mixing and charged lepton flavour violations. Current experimental constraints from \mu to e\gamma allow the scale of the flavon symmetry not far above the electroweak scale.
Autor primario
Ye-Ling Zhou
(IPPP, Durham University)
Coautor
Dr.
Silvia Pascoli Pascoli
(IPPP - Durham University)
