1,295 research outputs found
The Maximal Neutrino Flux from Neutralino Annihilation in the Galactic Center
We discuss a robust and fairly model-independent upper bound on the possible
neutrino flux produced by neutralino annihilation in the center of our galaxy,
and show that its detection with present or future neutrino telescopes is
highly improbable. This bound is obtained by relating the neutrino flux to the
gamma flux that would be produced in the same annihilation processes, for which
measurements do exist.Comment: 4 pages, 4 figures, uses floatfl
Leptogenesis: a Link between the Matter-Antimatter Asymmetry and Neutrino Physics
We review the experimental evidence for a net baryon density in cosmology,
and the theoretical mechanism for producing it, called leptogenesis, which
relies on the creation of a lepton asymmetry at an intermediate step. The
naturality of this mechanism and its possible relations with neutrino
oscillations are outlined.Comment: 11 pages, 6 figures; presented at the XXXVIII Rencontres de Moriond:
Electroweak Interactions and Unified Theories, Les Arcs, France, 15-22 March
200
Supersymmetric penguin contributions to the decay b -> s gamma with non-universal squarks masses
We give explicit expressions for the amplitudes associated with the
supersymmetric contributions to the process: b -> s gamma in the context of
SUSY extensions of Standard Model with non-universal soft SUSY breaking terms.
From experimental data, we deduce the limits on the squark mass insertions
obtained from different contributions (gluinos, neutralinos and charginos).Comment: 13 pages, 6 figures, changes: added remarks and new referenc
Neutrino Indirect Detection of Neutralino Dark Matter in the CMSSM
We study potential signals of neutralino dark matter indirect detection by
neutrino telescopes in a wide range of CMSSM parameters. We also compare with
direct detection potential signals taking into account in both cases present
and future experiment sensitivities. Only models with neutralino annihilation
into gauge bosons can satisfy cosmological constraints and current neutrino
indirect detection sensitivities. For both direct and indirect detection, only
next generation experiments will be able to really test this kind of models.Comment: 16 pages, 19 figures; v4: a few clarifications and significant
improvement of reference
Indirect Detection of CMSSM Neutralino Dark Matter with Neutrino Telescopes
We review the prospects of detecting supersymmetric dark matter in the
framework of the Constrained Minimal Supersymmetric Standard Model, and compare
indirect with direct detection capabilities.Comment: 6 pages, 4 figures, presented by J. Orloff at the York IDM02 workshop
(http://www.shef.ac.uk/~phys/idm2002
Higgs self coupling measurement in e+e- collisions at center-of-mass energy of 500 GeV
Feasibility of the measurement of the trilinear self-couplings of the Higgs
boson is studied. Such a measurement would experimentally determine the
structure of the Higgs potential. Full hadronic and semi-leptonic final states
of the double-Higgs strahlung have been investigated.Comment: 10 pages, 5 tables, 8 figure
A Comparison of Lanthanum Hexaboride, Cold FIeld Emission and Thermal Field Emission Electron Guns for Low Voltage Scanning Electron Microscopy
A comparison of lanthanum hexaboride, cold W(310) field emission and Zr/W thermal field emission cathodes was made by calculating the current-spot size relationship for each, using comparable lenses, to determine which would be suitable for high current operation at 1 keV beam energy, with a focused beam diameter \u3c 0.05 ÎĽm. On the criteria of highest current, reasonable operating conditions for the gun for low noise operation and long term cathode stability it was found that the lanthanum hexaboride and cold field emission cathodes are inadequate or marginal and that the best performance is obtainable from the thermal field emission cathode
Standard Model Baryogenesis
Simply on CP arguments, we argue against a Standard Model explanation of
baryogenesis via the charge transport mechanism. A CP-asymmetry is found in the
reflection coefficients of quarks hitting the electroweak phase boundary
created during a first order phase transition. The problem is analyzed both in
an academic zero temperature case and in the realistic finite temperature one.
At finite temperature, a crucial role is played by the damping rate of
quasi-quarks in a hot plasma, which induces loss of spatial coherence and
suppresses reflection on the boundary even at tree-level. The resulting baryon
asymmetry is many orders of magnitude below what observation requires. We
comment as well on related works.Comment: 10 pages, CERN-TH. 7368/94, LPTHE Orsay-94/71, HD-THEP-94-2
Portal-Systemic Encephalopathy in Emergency Treatment of Cirrhosis and Bleeding Esophageal Varices
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