Neutralino decaying dark matter
Dr. Diego Restrepo
U Antioquia
Sala de Reuniones del IFIC – 2 planta baja
Monday, January 11th, 2010 at 12:00
Abstract
In supersymmetric models extended with an anomalous $U(1)_H$
different R-parity violating couplings can yield an unstable
neutralino. We show that in this context astrophysical and
cosmological constraints on neutralino decaying dark matter forbid
bilinear R-parity breaking neutralino decays and lead to a class of
purely trilinear R-parity violating scenarios in which the
neutralino is stable on cosmological scales. We have found that
among the resulting models some of them become suitable to explain
the observed anomalies in cosmic-ray electron/positron fluxes.
Cosmic antimatter: is there room for exotic sources?
Dr. Fiorenza Donato
INFN Torino
Sala Seminarios IFIC (Edf. Institutos Paterna)
Friday, February 26th, 2010 at 11:00
Abstract
I will review the theory of propagation of
cosmic antimatter and of the main experimental results on
positrons and antiprotons in cosmic rays.
The interpretations of the data in terms of astrophysical
sources will be presented, and the possible contribution of dark matter
annihilation in the galactic halo will be inspected.
I will address some perspectives in light of forthcoming space missions and
theoretical advancements.
Fermion masses and mixing from non-abelian discrete symmetries
Dr. Davide Meloni
U Wurzburg
Sala de Juntas del IFIC Paterna
Wednesday, February 17th, 2010 at 15:30
Abstract
In this seminar I will show how theories invariant under some
non-abelian discrete symmetries work in explaining the experimental
pattern of fermion masses and mixing. In particular, I will analyze the
case of S4, showing that in the neutrino sector this group
helps in reproducing the approximate Tri-Bimaximal mixing structure of the lepton mixing matrix. The extension to the quark sector of the S4 symmetry and its consequences
are also briefly discussed.
SARAH – A Tool for SUSY Model Builders
Florian Staub
Universität Würzburg
Sala de Juntas
Thursday, January 28th, 2010 at 12:00
Abstract
SARAH is a Mathematica package for building and studying supersymmetric models. It calculates for a given superpotential, gauge sector and set of field rotations the full Lagrangian of a model. With the new version of SARAH it is possible to calculate automatically all interactions for the different eigenstates and write model files for FeynArts and CompHep/CalcHep. In addition, the tadpole equations are calculated, gauge fixing terms can be given and ghost interactions are added, particles can be integrated out and non supersymmetric limits of the theory can be chosen. CP and flavor violation can easily be switched on or off.
Tri-bimaximal Mixing and Cabibbo Angle in S_4 Flavor Model with SUSY
Dr. Yusuke Shimizu
U Nigata, Japan
Sala de Juntas del IFIC Paterna
Wednesday, March 10th, 2010 at 11:00
Abstract
We present an S_4 flavor model to unify quarks and leptons in the framework of the SU(5) SUSY GUT.
Taking vacuum alignments of relevant gauge singlet scalars, we predict the quark mixing as well as the tri-bimaximal mixing of neutrino flavors.
Especially, the Cabibbo angle is predicted to be 15 degree in the limit of the vacuum alignment.
Considering the next leading order, we predict the deviation from the tri-bimaximal mixing.
Flavor symmetry also constraints the sleptons structure, then we discuss the FCNC.
Do cosmological data favor neutrino mass and Dark Energy coupled to Dark Matter?
Giuseppe La Vacca
Università Milano-Bicocca & INFN
Sala Seminarios IFIC
Tuesday, January 19th, 2010 at 12:30
Abstract
We consider cosmological models with dynamical Dark Energy (DE) coupled to Cold Dark Matter (CDM), while simultaneously allowing neutrinos to be massive. We compare these models with a wide range of cosmological data and find a strong correlation between coupling and neutrino mass. According to data, the statistically most favored models allow a strong coupling between CDM and DE, and a neutrino mass high enough to agree with the (claimed) result of the Heidelberg-Moscow experiment and however detectable soon by the KATRIN experiment. A cosmology with uncoupled DE keeps however within 2 sigma. But, should neutrino experiments detect a mass in the expected range, cosmologies with two independent dark component are excluded at > 4 sigma.
Unified Model of Fermion Masses with Wilson Line Flavor Symmetry Breaking
Dr. Gerhart Seidl
U Wurzburg
Sala de Juntas IFIC
Thursday, January 21st, 2010 at 12:00
Abstract
We present a supersymmetric SU(5) GUT model with a discrete non-Abelian flavor symmetry that is broken by Wilson lines. The model is formulated in 4+3 dimensions compactified on a manifold S^3/Z_n. Symmetry breaking by Wilson lines is topological and allows to realize the necessary flavor symmetry breaking without a vacuum alignment mechanism. The model predicts the hierarchical pattern of charged fermion masses and quark mixing angles. Small normal hierarchical neutrino masses are generated by the type-I seesaw mechanism. The non-Abelian flavor symmetry predicts to leading order exact maximal atmospheric mixing while the solar angle emerges from a variant of quark-lepton complementarity. As a consequence, the resulting leptonic mixing matrix is in excellent agreement with current data and could be tested in future neutrino oscillation experiments.
Neutrino asymmetry and growth of cosmological magnetic fields
Dr. Victor Semikoz
Izmiran
Sala de Reuniones del IFIC – 2 planta baja
Tuesday, May 4th, 2010 at 12:00
Abstract
Primordial cosmological hypermagnetic fields polarize the early Universe plasma prior the electroweak phase transition (EWPT). As a result of the long range parity violating gauge interaction present in the Standard Model their amplitude gets amplified, opening a new perturbative way of seeding the primordial Maxwellian magnetic field at EWPT. The dynamics of the magnetic helicity during the electroweak phase transition in the early Universe is studied. It is shown that the boundary surface between symmetric (hypermagnetic) phase and Maxwellian phase with a broken symmetry is a membrana for the separation of the magnetic helicity. Assuming the total linking number of knots of hypermagnetic field is negative, it is proved that the helicity rising in the Maxwellian phase is left-handed.
Neutrino propagation with random magnetic fields.
Prof Alexander Rez
Izmiran
Sala Juntas
Monday, March 29th, 2010 at 12:00
Abstract
Neutrino propagation with random magnetic fields is reviewed, with discussion of possible new effects.
nonstandard neutrino-quark interactions
Dr. Omar Miranda
CINVESTAV
Sala de Juntas
Monday, May 17th, 2010 at 15:30
Abstract
Dynamo in Context of Riemannian Geometry: A Mathematical Tool and Cosmological Applications
Prof Dmitry Sokoloff
Moscow State Univ
Sala de Reuniones del IFIC – 2 planta baja
Friday, May 7th, 2010 at 12:00
Abstract
Neutrino masses and mixing and different mass hierarchies in mu-nuSSM
Dr. Pradipta Ghosh
iacs – India
Sala Seminarios IFIC (Edf. Institutos Paterna)
Monday, July 26th, 2010 at 12:00
Abstract
mu-nuSSM is an R-parity violating non-minimal supersymmetric model of neutrino mass generation where right chiral neutrino superfields are used to solve the mu-problem of supersymmetry. An effective mu-term and Majorana masses for right chiral neutrinos at electroweak scale are generated after electroweak symmetry breaking.
TeV scale seesaw mechanism involving right-handed neutrinos and R-parity violation are together instrumental for the light neutrino mass generation. We show that in mu-nuSSM all three neutrinos acquire massat the tree level consistent with the three flavour global data even with
diagonal neutrino Yukawa couplings. We further show that inclusion of one-loop corrections can alter the tree level neutrino masses and mixing in a significant manner. We find that it is relatively easier to accommodate the normal hierarchical mass pattern compared to the inverted
hierarchical or quasi-degenerate case, with the ingression of one-loop radiative correction. Nice correlation between tree level neutrino mixing angles and ratios of R-parity violating two-body decay branching ratio of the lightest neutralino is a characteristic feature of this model.
These correlations were analyzed for different lightest neutralino composition and different neutrino mass hierarchy and together with the study of displaced vertices these can provide useful experimental
signature of mu-nuSSM at the Large Hadron Collider (LHC).
Neutrinos at the Terascale – a tale of 3.5 frontiers
Heinrich Päs
University of Dortmund
Sala de Reuniones del IFIC – 2 planta baja
Tuesday, July 27th, 2010 at 10:00
Abstract
Neutrinos are the only hint for physics beyond the Standard Model, while the hierarchy problem, gauge coupling unification and dark matter give rise to hope for a direct discovery of new physics at the LHC. Occam’s razor suggests that there might be a relation. In this talk I discuss 3.5 frontiers, where neutino physics might directly be related to new physics to be discovered in the unknown real of the Terascale:
-the Majorana frontier
-the Unification frontier
-the Flavor frontier
-the Exotics frontier
Discrete flavour groups for neutrino mixing
Prof Guido Altarelli
CERN & U Rome
Sala Seminarios IFIC (Edf. Institutos Paterna)
Monday, May 24th, 2010 at 15:00
Abstract
We present the status of the application of non abelian discrete groups to the theory of neutrino masses and mixing. Discrete groups are strongly indicated by the agreement of the Tri-Bimaximal (TB) mixing pattern with experiment. We discuss the achievements of this approach and the open problems that remain.
Fermion masses and mixings in a mu-tau symmetric SO(10)
Bhavik Kodrani
Physical Research Laboratory, India
Sala de Reuniones del IFIC – 2 planta baja
Tuesday, July 27th, 2010 at 15:30
Abstract
The mu-tau symmetry imposed on the neutrino mass matrix in the flavour basis is known to be quite predictive. We integrate this very specific neutrino symmetry into a more general framework based on the supersymmetric $SO(10)$ grand unified theory. Consequences of this scheme
are considered for fermion masses using both type-I and type-II seesaw mechanism. Small explicit breaking of the $\mu$-$\tau$ symmetry is then shown to provide a very good understanding of all the fermion masses and mixing. One obtains a very good fit to all observables in the context of
the type-I seesaw mechanism but type-II seesaw model also provides a good description except for the overall scale of the neutrino masses. Three major predictions on the leptonic mixing parameters in the type-I seesaw case are (1) the atmospheric mixing angle $\theta_{23}^{l}$ close to
maximal, (2) theta13^{l}$ close to the present upper bound and (3) negative but very small Dirac CP violating phase in the neutrino oscillations.
The Higgs as a harbinger of flavor symmetry
Philip Leser
University of Dortmund
Sala de Juntas
Tuesday, November 16th, 2010 at 16:00
Abstract
Discrete symmetries employed to explain flavor mixing and mass hierarchies are often associated with an enlarged scalar sector which might lead to exotic Higgs decay modes. We explore such a possibility in a scenario with S3 flavor
symmetry which requires three scalar SU(2) doublets. The spectrum is fixed by minimizing the scalar potential, and we observe that the symmetry of the model leads to tantalizing Higgs decay modes potentially observable at the CERN Large
Hadron Collider (LHC).
Dark matter models with large annihilation cross section
Valentina DiRomeri
IFIC
Friday, October 29th, 2010 at 15:00
Abstract
Hypermagnetic field as a seed of Maxwellian field: magnetic helicity transfer
Prof. Victor Semikoz
Izmiran
Sala de Juntas del IFIC – planta baja
Monday, November 15th, 2010 at 11:00
Abstract
Hypermagnetic field as a seed of Maxwellian field: magnetic helicity transfer
Prof. Victor Semikoz
Izmiran
Sala de Juntas del IFIC – planta baja
Thursday, November 18th, 2010 at 11:30
Abstract
Magnetic (hypermagnetic) helicity is the most important characteristic of the field structure: its conservation
is much more restrictive in astrophysical objects than the magnetic field energy conservation. Rotation of galaxies, stars, etc. feeds magnetic field energy (i.e. (B^2/8\pi)\sim amplitude^2 is growing due to dynamo).
Same rotation does not influence helicity at all. Only a small helicity parameter (parity violating in isotropic= not rotating early Universe) provides amplification both energy (amplitude) and magnetic helicity in primordial plasma.
The evolution of the magnetic helicity during the
electroweak phase transition (EWPT) in the early Universe is studied.
It is shown that the boundary surface between symmetric (hypermagnetic)
phase and Maxwellian phase with a broken symmetry is a membrana for
the separation of the magnetic helicity. The hypermagnetic helicity
converts into the magnetic one during EWPT and can be a supply of
galactic magnetic helicity. During short EWPT time the helicity
parameter \alpha plays no role: the bubble expansion of new broken phase
is more important. However, before EWPT the bigger the value
of a lepton (right electron) asymmetry \mu_{eR} the bigger helicity parameter
\alpha\sim \mu_{eR}/T and the effect of hypermagnetic helicity growth.
The Higgs as a harbinger of flavor symmetry
Leser Philip
University of Dortmund
Sala de Juntas
Tuesday, November 16th, 2010 at 16:00
Abstract
Discrete symmetries employed to explain flavor mixing and mass hierarchies are often associated with an enlarged scalar sector which might lead to exotic Higgs decay modes. We explore such a possibility in a scenario with S3 flavor symmetry which requires three scalar SU(2) doublets. The spectrum is fixed by minimizing the scalar potential, and we observe that the symmetry of the model leads to tantalizing Higgs decay modes potentially observable at the CERN Large Hadron Collider (LHC).
Flavour of Grand Unifications – what do neutrinos tell us?
Dr. Michal Malinsky
IFIC, Valencia
Sala Seminarios IFIC (Edf. Institutos Paterna)
Tuesday, November 23rd, 2010 at 11:00
Abstract
After a brief intro into Grand Unified Theories focusing on their potential implications for the SM flavour problem I’ll discuss some of the recent developments triggered by the need to accommodate the absolute neutrino mass scale bounds obtained from neutrino oscillations and cosmology.
Flavour of Grand Unifications – what do neutrinos tell us?
Dr. Michal Malinsky
IFIC, Valencia
Sala de Juntas II del IFIC – planta baja
Tuesday, November 23rd, 2010 at 15:00
Abstract
After a brief intro into Grand Unified Theories focusing on their potential implications for the SM flavour problem I’ll discuss some of the recent developments triggered by the need to accommodate the absolute neutrino mass scale bounds obtained from neutrino oscillations and cosmology.
New aspects of symmetry breaking in Grand Unified Theories
Di Luzio Luca
SISSA
Sala de Juntas del IFIC – planta baja
Monday, December 13th, 2010 at 12:00
Abstract
Only the minimal GUTs are usually subject to a thorough scrutiny by complementary observables such as the proton lifetime, the absolute neutrino mass scale and the matching with the effective SM flavor structure. In this respect, the
concept of minimality itself can be associated to the simplicity of the relevant Higgs sector. I will review some recent results on the Higgs sector of both ordinary and supersymmetric GUTs, focusing first on a class of minimal nonsupersymmetric SO(10) models, fallen into disuse about 30 years ago and now revived by the quantum level analysis, and then on the investigation of the minimal SM-compatible flipped SO(10) and E(6) supersymmetric Higgs models
Dark Matter candidate from the compactification on a Real Projective Plane
Bogna Kubik
Institut de Physique Nucleaire de Lyon
Sala Seminarios IFIC
Tuesday, December 14th, 2010 at 12:00
Abstract
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Estela Garces
CINVESTAV
Sala de Reuniones
Saturday, May 8th, 2010 at 15:30
Abstract
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Estela Garces
CINVESTAV
Sala de Reuniones
Saturday, May 8th, 2010 at 15:30
Abstract
Discussion of MINOS Results
Dr Hiroshi Nunokawa
PUC Rio de Janeiro
Sala de Reuniones
Monday, February 22nd, 2010 at 15:00
Abstract
Discussion on GLOBES
Estela Garces
CINVESTAV
Sala de Reuniones
Wednesday, May 19th, 2010 at 15:30
Abstract
If the Higgs mass is .. or what might be known by 2016
Dr. Michael Dittmar
CERN
Sala Seminarios IFIC (Edf. Institutos Paterna)
Monday, October 18th, 2010 at 15:30
Abstract
After more than 20 years of intense and detailed theoretical calculations and experimental simulations, the prospect to search for a Higgs like boson and to discover it at the 14 TeV LHC and for a given luminosity are well known. The LHC and its experiments have now started to operate at 7 TeV and some encouraging first experimental results, despite the still low luminosity,
have already been presented. After a short overview about these first LHC results, the perspectives for direct Higgs searches using a realistic(?) LHC road map up to early 2016 will be presented.
Assuming a few representative Higgs masses, implications for its discovery and the consequences for todays experimental constraints and the electroweak precision data will be discussed.
Neutrino mass hierarchy from core-collapse supernovae
Irene Tamborra
Università degli Studi di Bari
Sala Seminarios IFIC (Edf. Institutos Paterna)
Friday, October 15th, 2010 at 12:00
Abstract
In core-collapse supernovae, the neutrino density is high enough to make the effects of nu-nu interaction important. Neutrinos couple, inducing collective flavor changes. The most striking effects would be abrupt changes in the neutrino energy spectra (spectral splits) according to the neutrino mass hierarchy. We explain the occurrence of spectral splits in a three-flavor framework.
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