Showing papers by "J. M. Carmona published in 2005"

First results from the CERN axion solar telescope.

Abstract: Hypothetical axionlike particles with a two-photon interaction would be produced in the sun by the Primakoff process. In a laboratory magnetic field (``axion helioscope''), they would be transformed into x-rays with energies of a few keV. Using a decommissioned Large Hadron Collider test magnet, the CERN Axion Solar Telescope ran for about 6 months during 2003. The first results from the analysis of these data are presented here. No signal above background was observed, implying an upper limit to the axion-photon coupling ${g}_{a\ensuremath{\gamma}}l1.16\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}10}\text{ }{\mathrm{GeV}}^{\ensuremath{-}1}$ at 95% C.L. for ${m}_{a}\ensuremath{\lesssim}0.02\text{ }\mathrm{eV}$. This limit, assumption-free, is comparable to the limit from stellar energy-loss arguments and considerably more restrictive than any previous experiment over a broad range of axion masses.

First results from the CERN Axion Solar Telescope (CAST)

Abstract: Hypothetical axionlike particles with a two-photon interaction would be produced in the sun by the Primakoff process. In a laboratory magnetic field ("axion helioscope"), they would be transformed into x-rays with energies of a few keV. Using a decommissioned Large Hadron Collider test magnet, the CERN Axion Solar Telescope ran for about 6 months during 2003. The first results from the analysis of these data are presented here. No signal above background was observed, implying an upper limit to the axion-photon coupling g(agamma)<1.16x10(-10) GeV-1 at 95% C.L. for m(a) less, similar 0.02 eV. This limit, assumption-free, is comparable to the limit from stellar energy-loss arguments and considerably more restrictive than any previous experiment over a broad range of axion masses.

The Canfranc Underground Laboratory

Abstract: This paper describes the forthcoming enlargement of the Canfranc Underground Laboratory (LSC) which will allow to host new international Astroparticle Physics experiments and therefore to broaden the European underground research area. The new Canfranc Underground Laboratory will operate in coordination (through the ILIAS Project) with the Gran Sasso (Italy), Modane (France) and Boulby (UK) underground laboratories.

Status of the non-cryogenic dark matter searches at the Canfranc Underground Laboratory

Abstract: The status of the non-cryogenic dark matter searches at the Canfranc Underground Laboratory is presented. Latest results and future prospects of the IGEX-DM and ANAIS experiments are reported.

The CERN Axion Solar Telescope (CAST): an update

Abstract: The CERN Axion Solar Telescope (CAST), a 10 meter long LHC, 9 Tesla, test magnet is mounted on a moving platform that tracks the sun about 1.5 hours during sunrise, again during sunset. It moves ±8 0 vertically and ±40 0 horizontally. It has been taking data continuously since July 10, 2003. Data analyzed thus far yield an upper bound on the photon-axion coupling constant, g aγγ ⩽ 3 × 10 −10 GeV −1 for axion masses less than 5 × 10 −2 eV.

Relativity principle with a low energy invariant scale

Abstract: The possibility of a modification of special relativity with an invariant energy scale playing the role of a minimum energy is explored. Consistency with the equivalence of different inertial frames is obtained by an appropriate choice of a nonlinear action of the Lorentz group on momentum space. Limits on the low energy cutoff from tests of Einstein's theory and possible ways to measure the new energy scale are discussed.

Study of the neutron background at the Canfranc Underground Laboratory

Abstract: A quantitative study of the neutron environment in the Canfranc Underground Laboratory is being carried out, specially focused on the IGEX Dark Matter Experiment. A set of simulations based on GEANT4 and FLUKA codes together with data obtained in different experimental conditions in the IGEX set-up allow us to quantify the effect of neutrons in the low-energy spectrum of the IGEX-DM detector. As an intermediate result, we have estimated the flux of neutrons from radioactivity of the rock (4 × 10 − 6 n cm − 2 s − 1 ), the flux of muon-induced neutrons in the rock (2 × 10 − 9 n cm − 2 s − 1 ), and the rate of neutron production by muons in the lead shielding (4×10 − 9 n cm − 3 s − 1 ). As a first conclusion, 40 cm of neutron moderator should be enough to push far below the present level of sensitivity of the IGEX-DM detector, the contribution to the low energy region (from 4 to 10 keV) of neutrons coming from fission and ( α ,n) reactions in the rock. The contribution of muon-induced neutrons in the rock is also estimated to be far below the present level of sensitivity, so the residual background of IGEX-DM in the low energy region cannot be attributed to neutrons.