9 research outputs found
Lepton mixing and neutrino masses from A5 and CP
Some properties of lepton mixing and neutrino masses can be computed under
the assumption of A5 and CP as a symmetry in the leptonic sector. The results
show that four mixing patterns accommodate well the oscillation data, i.e. all
the mixing angles are in the 3sigma confidence region. We also introduce an
explicit realization of this framework in the case of the Weinberg operator
where the neutrino mass spectrum can be computed.Comment: Poster presented at NuPhys2015 (London, 16-18 December 2015). 5
pages, LaTeX, 2 pdf figure
Probability Densities of the effective neutrino masses and
We compute the probability densities of the effective neutrino masses
and using the Kernel Density Estimate (KDE)
approach applied to a distribution of points in the and planes, obtained using the available
Probability Distribution Functions (PDFs) of the neutrino mixing and mass
differences, with the additional constraints coming from cosmological data on
the sum of the neutrino masses. We show that the reconstructed probability
densities strongly depend on the assumed set of cosmological data: for a sensitive portion of the allowed values
are already excluded by null results of experiments searching for and , whereas in the case $\sum_j m_j \leq 0.23\ @\ 95\% \
\mathrm{CL}$ the bulk of the probability densities are below the current
bounds.Comment: 12 pages, 6 figures, 4 tables. Improved discussion and references
added, typos corrected, matches published version in NP
Phenomenology of SU(5) low-energy realizations: the diphoton excess and Higgs flavor violation
We discuss different low-energy realizations and illustrate their
use with the diphoton excess and Higgs flavor violation, which require new
physics at the TeV scale. In particular, we study two scenarios for a GeV
resonance: in the first one the resonance belongs to the adjoint of , being either an singlet or a triplet, while in the second
case the signal is due to the CP-even and CP-odd states of a new
Higgs doublet belonging to a or a representations,
giving rise to a two-Higgs doublet model at low energies. We study the
fine-tuning needed for the desired members of the multiplets to be light
enough, while having the rest at the GUT scale. In these scenarios, the
production and decay into photons of the new resonance are mediated by the
leptoquarks (LQ) present in these large representations. We analyse
the phenomenology of such scenarios, focusing on the most relevant predictions
that can help to disentangle the different models, like decays into gauge
bosons, Standard Model (SM) fermions and LQs pair production. In the case of
the (the Georgi-Jarlskog model), we also study the possibility to
have Higgs flavor violation. We find that mixing limits (in addition to
) always imply that .Comment: Minor clarifications and references added, typos corrected, matches
published version in NP
Neutrino masses and lepton mixing from
We analyse in detail the phenomenological implications for lepton masses and
mixing derived by the breaking of the discrete symmetries into
the subgroups in the neutrino sector and in the charged
lepton sector. We derive accurate analytic expressions for the sum of the
neutrino masses as well as for the effective Majorana masses
and under different hypotheses for the flavon vevs
and compare them with the exact numerical results obtained from the
diagonalization of the neutrino mass matrix.Comment: 40 pages, 9 figure
Lepton mixing from the interplay of the alternating group A5 and CP
Abstract: Assuming three generations of Majorana neutrinos, we study the different mixing patterns that arise from the non-trivial breaking of the flavor group A5 and CP to the residual symmetries Z3, Z5 or Z2 × Z2 in the charged lepton and to Z2 × CP in the neutrino sector. All patterns contain only one free parameter θ and thus mixing angles as well as the Dirac and the two Majorana phases are strongly correlated. We perform an analytical and a numerical study of all possible mixing patterns. It turns out that only four patterns can describe the experimentally measured values of the mixing angles for a particular choice of θ well. All of them predict trivial Majorana phases, while the Dirac phase δ is maximal for two patterns and trivial for the two remaining ones. If δ is maximal, also the atmospheric mixing angle is fixed to be maximal