The Epoch of Reionization
A three-parameter model for the neutrino mass matrix
Fermion masses in E6 with S3 permutation symmetry
is not manifest in the quark sector. Assuming E6 as unified gauge group it is possible to make a distinction between neutrino and charged fermions.
Current Status of Cosmological Inflation
Flavour Matters in Leptogenesis
Test of lepton flavour violation at LHC
and sleptons within the Minimal Supersymmetric Standard Model.
Taking into account the most recent bounds on flavour violating rare
lepton decays, we study the impact of the lepton flavour violating
neutralino and slepton decays on the di-lepton mass distributions
measured at LHC. We find that they can result in novel and characteristic
edge structures in the distributions, which provides a powerful test of
supersymmetric lepton flavour violation at LHC.
Model for fermion masses and lepton mixing in SO(10)xA4
to grand unified models since in general left-handed and right-handed fields belong to different A4 representations. Recently it has been proposed a model where all the fermions equally transform under A4. We study an SO(10) realization of such a model giving a seesaw realization for neutrino masses. We fit fermion mass hierarchies. Our model predict the absolute value of the neutrino masses to be 0.052eV, and lepton mixing angles are consequence of the A4 properties.
Large-scale cosmological magnetic fields and magnetic helicity
We discuss possible mechanisms for cosmological magnetic field production in the early universe as well as upper observationl estimate for such field. In particular, primordial magnetic field generation driven by weak interaction of charged leptons with neutrinos is an efficent way for production of large-scale fields. The general conclusion is that the substantial cosmological field with a non-vanishing helicity can be generated in the early universe and survive up to the epoch of galaxy formation.
Multi-GeV neutrinos due to neutron anti-neutron oscillation in Gamma-Ray Burst Fireballs
collapse of massive stars and merger of compact binaries respectively. All these
objects are rich in neutron and the jet outflow from these objects must have a
neutron component in it. By postulating the neutron anti-neutron oscillation in
the gamma-ray burst fireball, we show that, 19-38 GeV neutrinos and
anti-neutrinos can be produced due to annihilation of anti-neutrons with the
background neutrons. These neutrinos and anti-neutrinos will be produced before
the 5-10 GeV neutrinos due to dynamical decoupling of neutrons from the rest of
the fireball. Observation of these neutrinos will shed more light on the nature
of the GRB progenitors and also be a unique signature of physics beyond the
standard model. A possible way of detecting these neutrinos in future is also
discussed.
A new insight in the solar core
Neutrino masses, SUSY breaking and LFV in the triplet seesaw model
where the exchange of heavy SU(2)_W triplet states generates both neutrino
masses and soft supersymmetry breaking terms. This framework turns out to be
highly predictive since it contains only three free parameters connecting
low-energy neutrino parameters, lepton and quark flavour violation,
sparticle and Higgs boson spectra and electroweak symmetry breakdown. We
perform a complete analysis of the parameter space taking into account the
present experimental constraints and considering different types of neutrino
mass spectrum. A special emphasis is given to the particular features of the
sparticle and Higgs spectra and to LFV processes like mu-> e X, mu-> e
conversion in nuclei, tau-> e Y and tau-> mu Y (X = gamma, e e, Y= gamma, e
e, mu mu).
SUSY Search at future colliders and dark matter experiments
Higgsino. I also describe their signatures at future colliders. as well as in Dark matter experiments.
Dark matter constraints from X-ray observations
Several dark matter candidates including the sterile neutrino,
specific Kaluza Klein axions and majorons are allowed to decay into
X-rays, with a characteristic signature. I present the results of
searches for such signatures using Chandra X-ray data of dark matter
dominated regions, and the obtained constraints for the dark matter
candidates.
First steps toward Ultra High-Energy Cosmic-Ray Astronomy
R-Parity Violation: Neutrino Masses and Collider Signals
neutrino masses and mixings. One interesting feature of this scenario is
that the
lightest supersymmetric particle is unstable and its decay can be
observed at high energy colliders, providing a falsifiable test of
the model. We discuss some aspects of the SUSY phenomenology at
colliders in the framework of this model.
R-Parity Violation: Neutrino Masses and Collider Signals
neutrino masses and mixings. One interesting feature of this scenario is
that the
lightest supersymmetric particle is unstable and its decay can be
observed at high energy colliders, providing a falsifiable test of
the model. We discuss some aspects of the SUSY phenomenology at
colliders in the framework of this model.
Probing non-standard neutrino interactions with supernova neutrinos.
Non-standard neutrino interactions and low energy neutrino experiments
physics beyond the Standard Model, and they can have an important
influence in the solar neutrino analysis. In this talk, after a
discussion of the solar neutrino data I will concentrate in present
and future low-energy experiments and their sensitivity to NSI. It
will be shown that these type of experiments could give constraints
that are competitive with other future proposals such as neutrino
factories.
Neutrino magnetic moment, Borexino and unparticle interactions
We fit the Borexino data by including a new term in the cross section, according to the presence of a non zero magnetic moment for the neutrinos, a NSI, or a non zero coupling between leptons and unparticles.
Selectron production at an e- e- linear collider with transversely polarized beams
A tight link between baryogenesis and the neutrino mass in SO(10) theories
produced from leptogenesis depends on light neutrino data
but also on several unknown parameters,
related to the very high energy scale where lepton number is broken.
In SO(10) Grand Unified Theories, leptogenesis models become more
predictive,
but the freedom in the choice of parameters is only partially reduced.
In this talk I will point out that, in a new class of SO(10)
models, one single
coupling induces neutrino masses as well as a lepton and baryon asymmetry.
The asymmetry is in fact proportional to
${\rm Im}[m^*_{11} (m\,m^*\,m)_{11}]$, where $m$ is the light
neutrino mass matrix.
Therefore, this new mechanism
relates baryogenesis directly to low energy neutrino parameters.
Sneutrino cold dark matter, a new analysis: relic abundance
and detection rates
candidates is presented. We first revisit the canonical Minimal
Supersymmetric Standard Model, concluding that sneutrinos are not yet
fully excluded, although only marginally compatible with existing
experimental bounds when they constitute a largely subdominant
component of dark matter. We then discuss supersymmetric models which
include right-handed fields and/or lepton-number violating terms.
Simple versions of the lepton-number-violating models do not lead to
phenomenology different from the standard case when the bounds
arising from the neutrino mass sector are included. On the contrary,
models with right-handed fields, in addition to provide a merchanism
for the generation of the neutrino mass, are perfectly viable: they
predict sneutrinos which are compatible with the current direct
detection sensitivities, both as subdominant and dominant dark matter
components. We then study the indirect detection signals for such
successful models: predictions for antiproton, antideuteron and gamma-
ray fluxes are provided and compared with existing and future
experimental sensitivities. The neutrino flux from the center of the
Earth is also analyzed. We conclude that models where the neutrino
mass is generated via the see-saw mechanism with a TeV scale Majorana
mass are the most interesting for the sneutrino dark matter sector.
If you wish to give a AHEP seminar please, fill in this form
See also the IFIC - CSIC/UVEG seminar list
See also the IFIC - CSIC/UVEG seminar list