0000000000017117
AUTHOR
Salvador Centelles Chuliá
Theory and phenomenology of Dirac neutrinos: Symmetry breaking patterns, flavour implications and Dark Matter
El Modelo Estándar (SM en ingles) de interacciones Electro-Débiles (EW en inglés) ha sido un gran éxito desde un punto de vista teórico y experimental. Si bien este éxito no se puede negar, es hora de avanzar y abordar las preguntas que el SM deja sin respuesta, como las masas de neutrinos, la naturaleza de la materia oscura, el problema de la jerarquía o el problema de violación de CP en el sector de las interacciones fuertes, entre otros. De hecho, el SM predice neutrinos sin masa. Sin embargo, los experimentos de oscilación de neutrinos, que ahora alcanzan la era de la precisión, muestran claramente que al menos dos neutrinos son masivos y arrojan luz sobre su patrón de mezcla. Sin embar…
Neutrino oscillations from warped flavor symmetry: predictions for long baseline experiments T2K, NOvA and DUNE
Here we study the pattern of neutrino oscillations emerging from a previously proposed warped model construction incorporating $\Delta(27)$ flavor symmetry. In addition to a complete description of fermion masses, the model predicts the lepton mixing matrix in terms of two parameters. The good measurement of $\theta_{13}$ makes these two parameters nearly proportional, leading to an approximate one-parameter description of neutrino oscillations. There is a sharp fourfold degenerate correlation between $\delta_{CP}$ and the atmospheric mixing angle $\theta_{23}$, so that maximal $\theta_{23}$ also implies maximal leptonic CP violation. The predicted electron neutrino and anti-neutrino appear…
The Inverse Seesaw Family: Dirac And Majorana
After developing a general criterion for deciding which neutrino mass models belong to the category of inverse seesaw models, we apply it to obtain the Dirac analogue of the canonical Majorana inverse seesaw model. We then generalize the inverse seesaw model and obtain a class of inverse seesaw mechanisms both for Majorana and Dirac neutrinos. We further show that many of the models have double or multiple suppressions coming from tiny symmetry breaking "$\mu$-terms". These models can be tested both in colliders and with the observation of lepton flavour violating processes.
Scotogenic dark symmetry as a residual subgroup of Standard Model symmetries
We show that the scotogenic dark symmetry can be obtained as a residual subgroup of the global $U(1)_{B-L}$ symmetry already present in Standard Model. We propose a general framework where the $U(1)_{B-L}$ symmetry is spontaneously broken to an even $\mathcal{Z}_{2n}$ subgroup, setting the general conditions for neutrinos to be Majorana and the dark matter stability in terms of the residual $\mathcal{Z}_{2n}$. Under this general framework, as examples, we build a class of simple models where, in the scotogenic spirit, the dark matter candidate is the lightest particle running inside the neutrino mass loop. The global $U(1)_{B-L}$ symmetry in our framework being anomaly free can also be gaug…
Realistic Tri-Bi-Maximal neutrino mixing
We propose a generalized version of the Tri-Bi-Maximal (TBM) ansatz for lepton mixing, leading to non-zero reactor angle $\theta_{13}$ and CP violation. The latter is characterized by two CP phases. The Dirac phase affecting neutrino oscillations is nearly maximal ($\delta_{CP} \sim \pm \pi/2$), while the Majorana phase implies narrow allowed ranges for the neutrinoless double beta decay amplitude. The solar angle $\theta_{12}$ lies nearly at its TBM value, while the atmospheric angle $\theta_{23}$ has the TBM value for maximal $\delta_{CP}$. Neutrino oscillation predictions can be tested in present and upcoming experiments.