Large Scale Structure and Cosmic Rays revisited

We investigate the possibility that ultra high energy cosmic rays (E > 10^19 eV) are related to the distribution of matter on large scales. The large scale structure (LSS) data stems from the recent IRAS PSCz redshift survey. We present preliminary predictions drawn from an anisotropic distribution of sources which follows the galaxy distribution.Comment: 6 pages, 2 figures, uses World Scientific style. To appear in the proceedings of "Third International Workshop on New Worlds in Astro-Particle Physics", 1-3 Set. 2000, Faro, Portugal and X ENAA, 27-28 Jul. 2000, Lisbon, Portuga

Search for 2νββ decay of ^(136)Xe to the 0^+^1 excited state of ^(136)Ba with the EXO-200 liquid xenon detector

EXO-200 is a single phase liquid xenon detector designed to search for neutrinoless ββ decay of ^(136)Xe to the ground state of ^(136)Ba. We report here on a search for the two-neutrino ββ decay of 136Xe to the first 0+ excited state, 0^+_1, of ^(136)Ba based on a 100 kg yr exposure of ^(136)Xe. Using a specialized analysis employing a machine learning algorithm, we obtain a 90% CL half-life sensitivity of 1.7 × 10^(24) yr. We find no statistically significant evidence for the 2νββ decay to the excited state resulting in a lower limit of T^(2ν)_(1/2)(0^+ → 0^+_1) > 6.9 ×10^(23) yr at 90% CL. This observed limit is consistent with the estimated half-life of 2.5 × 10^(25) yr

Polarization Correlations in Pair Production from Charged and Neutral Strings

Polarization correlations of $e^{+}e^{-}$ pair productions from charged and neutral Nambu strings are investigated, via photon and graviton emissions, respectively and explicit expressions for their corresponding probabilities are derived and found to be \textit{speed} dependent. The strings are taken to be circularly oscillating closed strings, as perhaps the simplest solution of the Nambu action. In the extreme relativistic case, these probabilities coincide, but, in general, are different, and such inquiries, in principle, indicate whether the string is charged or uncharged. It is remarkable that these dynamical relativistic quantum field theory calculations lead to a clear violation of Local Hidden Variables theories.Comment: 6 pages, no figure, LaTeX with ws-mpla.cl

Status of the PICASSO Project

The Picasso project is a dark matter search experiment based on the superheated droplet technique. Preliminary runs performed at the Picasso Lab in Montreal have showed the suitability of this detection technique to the search for weakly interacting cold dark matter particles. In July 2002, a new phase of the project started. A batch of six 1-liter detectors with an active mass of approximately 40g was installed in a gallery of the SNO observatory in Sudbury, Ontario, Canada at a depth of 6,800 feet (2,070m). We give a status report on the new experimental setup, data analysis, and preliminary limits on spin-dependent neutralino interaction cross section.Comment: 3 pages, 2 figures. To appear in the Proceedings of the TAUP 2003 conference, 5-9 September, 2003, University of Washington, Seattle, US