53 research outputs found
IceCube expectations for two high-energy neutrino production models at active galactic nuclei
We have determined the currently allowed regions of the parameter spaces of
two representative models of diffuse neutrino flux from active galactic nuclei
(AGN): one by Koers & Tinyakov (KT) and another by Becker & Biermann (BB). Our
observable has been the number of upgoing muon-neutrinos expected in the
86-string IceCube detector, after 5 years of exposure, in the range 10^5 <
E/GeV < 10^8. We have used the latest estimated discovery potential of the
IceCube-86 array at the 5-sigma level to determine the lower boundary of the
regions, while for the upper boundary we have used either the AMANDA upper
bound on the neutrino flux or the more recent preliminary upper bound given by
the half-completed IceCube-40 array (IC40). We have varied the spectral index
of the proposed power-law fluxes, alpha, and two parameters of the BB model:
the ratio between the boost factors of neutrinos and cosmic rays,
Gamma_nu/Gamma_{CR}, and the maximum redshift of the sources that contribute to
the cosmic-ray flux, zCRmax. For the KT model, we have considered two
scenarios: one in which the number density of AGN does not evolve with redshift
and another in which it evolves strongly, following the star formation rate.
Using the IC40 upper bound, we have found that the models are visible in
IceCube-86 only inside very thin strips of parameter space and that both of
them are discarded at the preferred value of alpha = 2.7 obtained from fits to
cosmic-ray data. Lower values of alpha, notably the values 2.0 and 2.3 proposed
in the literature, fare better. In addition, we have analysed the capacity of
IceCube-86 to discriminate between the models within the small regions of
parameter space where both of them give testable predictions. Within these
regions, discrimination at the 5-sigma level or more is guaranteed.Comment: 24 pages, 6 figures, v2: new IceCube-40 astrophysical neutrino upper
bound and IceCube-86 discovery potential used, explanation of AGN flux models
improved, only upgoing neutrinos used, conclusions strengthened. Accepted for
publication in JCA
Virtual coupling potential for elastic scattering of Be on proton and carbon targets
International audienceThe 10;11Be(p,p) and (12C, 12C) reactions were analyzed to determine the in uence of the weak binding energies of exotic nuclei on their interaction potential. The elastic cross sections were measured at GANIL in inverse kinematics using radioactive 10;11Be beams produced at energies of 39:1 A and 38:4A MeV. The elastic proton scattering data were analyzed within the framework of the microscopic Jeukenne-Lejeune-Mahaux (JLM) nucleon-nucleus potential. The angular distributions are found to be best reproduced by reducing the real part of the microscopic optical potential, as a consequence of the coupling to the continuum. These effects modify deeply the elastic potential. Including the Virtual Coupling Potential (VCP), we show the ability of the general optical potentials to reproduce the data for scattering of unstable nuclei, using realistic densities. Finally, the concepts needed to develop a more general and microscopic approach of the VCP are discussed
Coupling effects in the elastic scattering of He on C
To study the effect of the weak binding energy on the interaction potential between a light exotic nucleus and a target, elastic scattering of 6He at 38.3 MeV/nucleon on a 12C target was measured at Grand Accélérateur National d'Ions Lourds (GANIL). The 6He beam was produced by fragmentation. The detection of the scattered particles was performed by the GANIL spectrometer. The energy resolution was good enough to separate elastic from inelastic scattering contributions. The measured elastic data have been analyzed within the optical model, with the real part of the optical potential calculated in the double-folding model using a realistic density-dependent nucleon-nucleon interaction and the imaginary part taken in the conventional Woods-Saxon (WS) form. A failure of the "bare" real folded potential to reproduce the measured angular distribution over the whole angular range suggests quite a strong coupling of the higher-order breakup channels to the elastic channel. To estimate the strength of the breakup effects, a complex surface potential with a repulsive real part (designed to simulate the polarization effects caused by the projectile breakup) was added to the real folded and imaginary WS potentials. A realistic estimate of the polarization potential caused by the breakup of the weakly bound 6He was made based on a parallel study of 6He+12C and 6Li+12C optical potentials at about the same energies
Progress Report on Target Development
The present document is the D08 deliverable report of work package 1 (Target Development) from the MEGAPIE TEST project of the 5th European Framework Program. Deliverable D08 is the progress report on the activities performed within WP 1. The due date of this deliverable was the 5th month after the start of the EU project. This coincided with a technical status meeting of the MEGAPIE Initiative, that was held in March 2002 in Bologna (Italy). The content of the present document reflects the status of the MEGAPIE target development at that stage. It gives an overview of the Target Design, the related Design Support activities and the progress of the work done for the safety assessment and licensing of the target
Long-Baseline Neutrino Facility (LBNF) and Deep Underground Neutrino Experiment (DUNE) Conceptual Design Report Volume 2: The Physics Program for DUNE at LBNF
The Physics Program for the Deep Underground Neutrino Experiment (DUNE) at the Fermilab Long-Baseline Neutrino Facility (LBNF) is described
Fc gamma Receptor III and Fc gamma Receptor IV on Macrophages Drive Autoimmune Valvular Carditis in Mice
Tumourgenetics and immunogenetic
Temperature-Compensated Structure For Saw Pressure Sensor In Very High Temperature
International audienceThis paper concerns the design and the analysis of a surface acoustic wave (SAW) pressure sensor that is capable to work in high temperature (up to 800degC) environment. Novel structures of the device are also presented for self-temperature compensation. Special attention is made on the different possible multilayer structures that could be used, the behavior of the sensor, the electromechanical coupling factor, the wave velocity as well as the required RF matching circuit. These parameters are critical issues for this special SAW sensor
Trade-Off between Issues in AlN/SiO2/Si Pressure Sensor
International audienceThe design, modeling, fabrication process of a novel AIN/SiO2/Si surface acoustic wave (SAW) pressure sensor are introduced. Self temperature compensation structure is given. Special attention is made on the different possible multilayer structures that could be used, trade-off between parameters of pressure sensor
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