135 research outputs found
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 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
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