Séminaire à deux voix : M. Cirelli et Y. Hatta
M. Cirelli/ Y. Hatta
SPhT
Tue, Nov. 07th 2006, 11:00
Salle Claude Itzykson, Bât. 774, Orme des Merisiers
M. Cirelli (SPhT)
Picturing Dark Matter form its Neutrinos.
Dark Matter constitutes about one fourth of the contents of the
Universe, yet we know almost anything on its nature. A way to
(hopefully soon) detect Dark Matter, albeit indirectly, is to collect
at the Neutrino Telescopes (huge Cerenkov experiments located under-
water or under-ice) the fluxes of high energy neutrinos that should
be produced by the annihilations of DM particles accumulated in the
center of the Earth and the Sun. The neutrino fluxes carry precious
information on the main properties of DM (its abundance, its mass and
its annihilation branching ratios), opening windows on its nature and
on the theory that explains it.
I present the work with which we computed precisely the expected
yield of neutrinos of all flavors and, especially, the neutrino
spectra, which are more free from astrophysical uncertainties. We
developed the appropriate formalism to follow the neutrino
production, the evolution of the fluxes in the matter of the Earth
and the Sun and in the vacuum and finally several kinds of detection
signatures.
Based on: hep-ph/0506298, Nucl.Phys.B727,99-138(2005)
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Y. Hatta (SPhT)
Small-x physics in QCD and the color glass condensate.
I review recent developments in the theory of high energy
scattering in QCD. After explaining the violation of
unitarity in the standard perturbative calculation, I
discuss the semiclassical approach to the problem of
unitarity restoration based on the idea of gluon
saturation.