25 research outputs found
Fourth Lepton Family is Natural in Technicolor
Imagine to discover a new fourth family of leptons at the Large Hadron
Collider (LHC) but no signs of an associated fourth family of quarks. What
would that imply? An intriguing possibility is that the new fermions needed to
compensate for the new leptons gauge anomalies simultaneously address the big
hierarchy problem of the Standard Model. A natural way to accomplish such a
scenario is to have the Higgs itself be composite of these new fermions. This
is the setup we are going to investigate in this paper using as a template
Minimal Walking Technicolor. We analyze a general heavy neutrino mass structure
with and without mixing with the Standard Model families. We also analyze the
LHC potential to observe the fourth lepton family in tandem with the new
composite Higgs dynamics. We finally introduce a model uniting the fourth
lepton family and the technifermion sector at higher energies.Comment: 39 ReVTeX pages, 16 figure
Hints of a Charge Asymmetry in the Electron and Positron Cosmic-Ray Excesses
By combining the recent data from AMS-02 with those from Fermi-LAT, we show
the emergence of a charge asymmetry in the electron and positron cosmic-ray
excesses, slightly favoring the electron component. Astrophysical and dark
matter inspired models introduced to explain the observed excesses can be
classified according to their prediction for the charge asymmetry and its
energy dependence. Future data confirming the presence of a charge asymmetry,
would imply that an asymmetric production mechanism is at play.Comment: v1: 15 pages, 5 figures; v2: 15 pages, 5 figures, text and references
improved, published versio
Cosmic Sum Rules
We introduce new sum rules allowing to determine universal properties of the
unknown component of the cosmic rays and show how they can be used to predict
the positron fraction at energies not yet explored by current experiments and
to constrain specific models.Comment: RevTeX, 4 pages, 6 figures, two-columns. Final version to match the
published version in Brief Reports section of Phys. Rev. D. We stress that
this is the first paper about charge asymmetries in cosmic ray
Preliminary experimental identification of a FEM human knee model
A customizable Finite Elements Model of human knee is proposed for improving inter-individual reproducibility in NSAIDs transdermal delivery measurement. The model simulates: (i) the measurement system, based on Bio-Impedance Spectroscopy, and (ii) the system under test, namely the knee by five parallel, homogeneous, and concentric layers: bone, muscle, adipose tissue, wet skin, and dry skin. In this paper, first the equations and the architecture of the model are described. Then, the results of the numerical characterization and the preliminary experimental validation are reported. A sensitivity analysis was realized for reducing computational burden during Model customization. Only five parameters out of the 64 used in the Cole-Cole equation were sufficient for fitting experimental data of different subjects
A finite element model of abdominal human tissue for improving the accuracy in insulin absorption assessment: A feasibility study
A Finite Element Model of the human abdomen biomechanics for patients undergoing diabetes therapies was developed. In particular, FEM was used to improve a previous insulin absorption measurement method based on bioimpedance spectroscopy (BIS). As a matter of facts, the noise introduced during the insulin injection phase significantly affects the BIS measurements. The noise, due to the pressure exerted on the abdomen tissue, arises sensibility issues on the signal correlated to the drug presence under the skin. In this study, the abdomen is modeled with three layers (skin, fat and muscle). A feasibility study about the decoupling of the mechanical deformation and the electrical dynamics is presented in order to model the effect of mechanical uncertainty sources (e.g., pressure exerted during the injection phase and/or breathing) on the impedance measurements. The proposed simplified model is realised by referring to the average values of skin, fat and muscle thickness, along with mechanical abdomen parameters al-ready presented and validated in scientific literature. The obtained results confirm the possibility to decouple me-chanical and electrical analyses when the excitation voltage is characterized by a frequency higher than 1 kHz. The results will be used to improve the accuracy of an exhaustive approach, already developed by the authors, for real-time insulin absorption measurement
Gamma Ray Constraints on Flavor Violating Asymmetric Dark Matter
We show how cosmic gamma rays can be used to constrain models of asymmetric
Dark Matter decaying into lepton pairs by violating flavor. First of all we
require the models to explain the anomalies in the charged cosmic rays measured
by PAMELA, FERMI and HESS; performing combined fits we determine the allowed
values of the Dark Matter mass and lifetime. For these models, we then
determine the constraints coming from the measurement of the isotropic
gamma-ray background by FERMI for a complete set of lepton flavor violating
primary modes and over a range of DM masses from 100 GeV to 10 TeV. We find
that the FERMI constraints rule out the flavor violating asymmetric Dark Matter
interpretation of the charged cosmic ray anomalies.Comment: 11 pages, 3 figures. v2: constraints derivation slightly modified,
conclusions unchanged; some clarifications and some references added; matches
version published on JCA
Charge Asymmetric Cosmic Rays as a probe of Flavor Violating Asymmetric Dark Matter
The recently introduced cosmic sum rules combine the data from PAMELA and
Fermi-LAT cosmic ray experiments in a way that permits to neatly investigate
whether the experimentally observed lepton excesses violate charge symmetry.
One can in a simple way determine universal properties of the unknown component
of the cosmic rays. Here we attribute a potential charge asymmetry to the dark
sector. In particular we provide models of asymmetric dark matter able to
produce charge asymmetric cosmic rays. We consider spin zero, spin one and spin
one-half decaying dark matter candidates. We show that lepton flavor violation
and asymmetric dark matter are both required to have a charge asymmetry in the
cosmic ray lepton excesses. Therefore, an experimental evidence of charge
asymmetry in the cosmic ray lepton excesses implies that dark matter is
asymmetric.Comment: 12 pages, 8 figures. Revised version to match the published versio