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 ($\simeq 30$) with a high angular resolution (10 arcminutes) and a high sensitivity ($60\mu K$ per pixel). Archeops will perform a measurement of the CMB anisotropies power spectrum from large angular scales ($\ell\simeq 30$) to small angular scales ($\ell \simeq 800$). 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