463 research outputs found
Archeops, mapping the CMB sky from large to small angular scales
Archeops is a balloon-borne experiment designed to measure the temperature
fluctuations of the CMB on a large region of the sky () with a high
angular resolution (10 arcminutes) and a high sensitivity ( per
pixel). Archeops will perform a measurement of the CMB anisotropies power
spectrum from large angular scales () to small angular scales
(). Archeops flew for the first time for a test flight in July
1999 from Sicily to Spain and the first scientific flight took place from
Sweden to Russia in January 2001. The data analysis is on its way and I present
here preliminary results, realistic simulations showing the expected accuracy
on the measurement of the power spectrum and perspectives for the incoming
flights (Winter 2001/2003).Comment: 6 pages, 6 figures, proceedings to TAUP2001 conference, LNGS, Italy,
Sept. 200
Primordial Nucleosynthesis: an updated comparison of observational light nuclei abundances with theoretical predictions
An up to date review of Standard Big Bang Nucleosynthesis predictions vs the
astrophysical estimates of light nuclei abundances is here presented. In
particular the analysis reports the expected ranges for baryon fraction and
effective number of neutrinos as obtained by BBN only.Comment: 5 pages, 4 figures, to appear in the proceedings of NOW 200
Reconstructing Dark Matter Density with e^+e^- Linear Collider in Focus-Point Supersymmetry
It has been known that, in the focus point scenario of supersymmetry, the
thermal relic of the lightest superparticle (LSP) is known to be a good
candidate of the cold dark matter. Assuming that the LSP in the focus-point
scenario be the cold dark matter, we address a question how and how well the
relic density of the LSP can be determined once the superparticles are found at
future e^+e^- linear collider. We will see that the determinations of the mass
of the LSP as well as those of the Higgsino-like chargino and neutralinos,
which will be possible by a study of the decay kinematics of the chargino or by
threshold scan, will give us important information to theoretically reconstruct
the relic density. Even if the Higgsino-like superparticles and the LSP are the
only superparticles which are kinematically accessible, relic density of the
LSP may be calculated with the accuracy of factor \sim 2; by adopting a mild
theoretical assumption or by determining the masses of the Wino-like
superparticles, uncertaintiy can be reduced to \sim 10 % or smaller.Comment: 13 pages, 4 figure
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