3,548 research outputs found
Neutrino masses and mixings in a Minimal S_3-invariant Extension of the Standard Model
The mass matrices of the charged leptons and neutrinos, that had been derived
in the framework of a Minimal S_3-invariant Extension of the Standard Model,
are here reparametrized in terms of their eigenvalues. The neutrino mixing
matrix, V_PMNS, is then computed and exact, explicit analytical expressions for
the neutrino mixing angles as functions of the masses of the neutrinos and
charged leptons are obtained. The reactor, theta_13, and the atmosferic,
theta_23, mixing angles are found to be functions only of the masses of the
charged leptons. The numerical values of theta_13{th} and theta_23{th} computed
from our theoretical expressions are found to be in excellent agreement with
the latest experimental determinations. The solar mixing angle, theta_12{th},
is found to be a function of both, the charged lepton and neutrino masses, as
well as of a Majorana phase phi_nu. A comparison of our theoretical expression
for the solar angle theta_12{th} with the latest experimental value
theta_12{exp} ~ 34 deg allowed us to fix the scale and origin of the neutrino
mass spectrum and obtain the mass values |m_nu1|=0.0507 eV, |m_nu2|=0.0499 eV
and |m_nu3|=0.0193 eV, in very good agreement with the observations of neutrino
oscillations, the bounds extracted from neutrinoless double beta decay and the
precision cosmological measurements of the CMB.Comment: To appear in the Proceedings of the XXIX Symposium on Nuclear
Physics, Cocoyoc, Mex., January 2006. Some typographical errors on formulae
correcte
Finite Theories after the discovery of a Higgs-like boson at the LHC
Finite Unified Theories (FUTs) are N = 1 supersymmetric Grand Unified
Theories (GUTs) which can be made finite to all-loop orders, based on the
principle of reduction of couplings, and therefore are provided with a large
predictive power. Confronting the predictions of SU(5) FUTs with the top and
bottom quark masses and other low-energy experimental constraints a light
Higgs-boson mass in the range M_h ~ 121-126 GeV was predicted, in striking
agreement with the recent discovery of a Higgs-like state around ~ 125.7 GeV at
ATLAS and CMS. Furthermore the favoured model, a finiteness constrained version
of the MSSM, naturally predicts a relatively heavy spectrum with coloured
supersymmetric particles above ~ 1.5 TeV, consistent with the non-observation
of those particles at the LHC. Restricting further the best FUT's parameter
space according to the discovery of a Higgs-like state and B-physics
observables we find predictions for the rest of the Higgs masses and the
s-spectrum.Comment: 17 pages, 4 figures. arXiv admin note: substantial text overlap with
arXiv:0712.363
The LHC Higgs Boson Discovery: Implications for Finite Unified Theories
Finite Unified Theories (FUTs) are N = 1 supersymmetric Grand Unified
Theories (GUTs) which can be made finite to all-loop orders, based on the
principle of reduction of couplings, and therefore are provided with a large
predictive power. We confront the predictions of an SU(5) FUT with the top and
bottom quark masses and other low-energy experimental constraints, resulting in
a relatively heavy SUSY spectrum, naturally consistent with the non-observation
of those particles at the LHC. The light Higgs boson mass is automatically
predicted in the range compatible with the Higgs discovery at the LHC.
Requiring a light Higgs-boson mass in the precise range of M_h = 125.6 +- 2.1
GeV favors the lower part of the allowed spectrum, resulting in clear
predictions for the discovery potential at current and future pp, as well as
future e+e- colliders.Comment: 31 pages, 3 figures, review prepared for IJMP
Finite Unified Theories confronted with low-energy phenomenology
Finite Unified Theories (FUTs) are N=1 supersymmetric Grand Unified Theories
that can be made all-loop finite. The requirement of all-loop finiteness leads
to a severe reduction of the free parameters of the theory and, in turn, to a
large number of predictions. Here SU(5) FUTs are investigated in the context of
low-energy phenomenology observables. We present a detailed scanning of these
FUTs, including theoretical uncertainties at the unification scale and applying
all phenomenological constraints. Taking into account the restrictions from the
top and bottom quark masses, we can discriminate between different models.
Including further low-energy constraints such as physics observables, the
bound on the lightest Higgs boson mass and the cold dark matter density, we
determine the predictions of the allowed parameter space for the Higgs boson
sector and the supersymmetric particle spectrum of the model.Comment: Submitted for the SUSY07 proceedings, 4 pages, LaTeX, 3 eps figures.
v2 one ref adde
Confronting Finite Unified Theories with Low-Energy Phenomenology
Finite Unified Theories (FUTs) are N=1 supersymmetric Grand Unified
Theories that can be made all-loop finite. The requirement of all-loop
finiteness leads to a severe reduction of the free parameters of the theory
and, in turn, to a large number of predictions. FUTs are investigated in the
context of low-energy phenomenology observables. We present a detailed scanning
of the all-loop finite SU(5) FUTs, where we include the theoretical
uncertainties at the unification scale and we apply several phenomenological
constraints. Taking into account the restrictions from the top and bottom quark
masses, we can discriminate between different models. Including further
low-energy constraints such as B physics observables, the bound on the lightest
Higgs boson mass and the cold dark matter density, we determine the predictions
of the allowed parameter space for the Higgs boson sector and the
supersymmetric particle spectrum of the selected model.Comment: 25 pages, 8 figures. Discussion on models and on cold dark matter
constraint extended, references added. Version to appear in JHE
Finite Unified Models
We present phenomenologically viable unified models which are finite
to all orders before the spontaneous symmetry breaking. In the case of two
models with three families the top quark mass is predicted to be 178.8 GeV.Comment: 13 pages, latex fil
Coulomb correlations of a few body system of spatially separated charges
A Hartree-Fock and Hartree-Fock-Bogoliubov study of a few body system of
spatially separated charge carriers was carried out. Using these variational
states, we compute an approximation to the correlation energy of a finite
system of electron-hole pairs. This energy is shown as a function of the
Coulomb coupling and the interplane distance. We discuss how the correlation
energy can be used to theoretically determine the formation of indirect
excitons in semiconductors which is relevant for collective phenomena such as
Bose-Einstein condensation (BEC).Comment: Conference EDISON16 (2009), 4 page
Muon g-2 through a flavor structure on soft SUSY terms
In this work we analyze the possibility to explain the muon anomalous
magnetic moment discrepancy within theory and experiment through lepton flavor
violation processes. We propose a flavor extended MSSM by considering a
hierarchical family structure for the trilinear scalar Soft-Supersymmetric
terms of the Lagranagian, present at the SUSY breaking scale. We obtain
analytical results for the rotation mass matrix, with the consequence of having
non-universal slepton masses and the possibility of leptonic flavour mixing.
The one-loop supersymmetric contributions to the leptonic flavour violating
process are calculated in the physical basis, with slepton
flavour mixed states, instead of using the well known Mass Insertion Method. We
present the regions in parameter space where the muon g-2 problem is either
entirely solved or partially reduced through the contribution of these flavor
violating processes.Comment: 21 pages, 7 figures. Changes on version 3: In order to obtain the
complete result for muon g-2 in the limit of non-flavor violation we added
the terms given in the appendix. We redid the graphics and numerical analysis
including these changes. We also corrected some typos and changed the order
of figure
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