S 111 and the polarization of the B[e] supergiants in the Magellanic Clouds

We have obtained linear polarization measurements of the Large Magellanic Cloud B[e] supergiant S 111 using optical imaging polarimetry. The intrinsic polarization found is consistent with the presence of an axisymmetric circumstellar envelope. We have additionally estimated the electron density for S 111 using data from the literature and revisited the correlation between polarization and envelope parameters of the B[e] supergiant stars using more recent IR calibration color data. The data suggest that the polarization can be indeed explained by electron scattering. We have used Monte Carlo codes to model the continuum polarization of the Magellanic B[e] supergiants. The results indicate that the electron density distribution in their envelopes is closer to a homogeneous distribution rather than an r$^{-2}$ dependence. At the same time, the data are best fitted by a spherical distribution with density contrast than a cylindrical distribution. The data and the model results support the idea of the presence of an equatorial disk and of the two-component wind model for the envelopes of the B[e] supergiants. Spectropolarimetry would help further our knowledge of these envelopes

High-Temperature Superconducting Level Meter for Liquid Argon Detectors

Capacitive devices are customarily used as probes to measure the level of noble liquids in detectors operated for neutrino studies and dark matter searches. In this work we describe the use of a high-temperature superconducting material as an alternative to control the level of a cryogenic noble liquid. Lab measurements indicate that the superconductor shows a linear behaviour, a high degree of stability and offers a very accurate determination of the liquid volume. This device is therefore a competitive instrument and shows several advantages over conventional level meters.Comment: 13 pages, 11 figures. Accepted for publication in JINS

Direct WIMP identification: Physics performance of a segmented noble-liquid target immersed in a Gd-doped water veto

We evaluate background rejection capabilities and physics performance of a detector composed of two diverse elements: a sensitive target (filled with one or two species of liquefied noble gasses) and an active veto (made of Gd-doped ultra-pure water). A GEANT4 simulation shows that for a direct WIMP search, this device can reduce the neutron background to O(1) event per year per tonne of material. Our calculation shows that an exposure of one tonne $\times$ year will suffice to exclude spin-independent WIMP-nucleon cross sections ranging from $10^{-9}$ pb to $10^{-10}$ pb.Comment: 17 pages, 5 figures. Version accepted for publication in JCA

Estudio y caracterización de algunas 5-E-aldoximino-4-glucosilaminopirimidinas

The reaction between 1,6-dihydro-5-formil-4-β-D-(tetra-O-acetyl)glucopyranosylamino-1-methyl-2-methoxy-6-oxo-pyrimidine and an excess of ClH.H2NOH yields 5-E-aldoximine derivative as the only product. On the basis of its chemical behaviour and espectroscopic data we propose its structure.La reacción de 1,6-dihidro-5-formil-4-β-D-(2 ', 3 ' 4 ', 6 '-tetra-O-acetil)-glucopiranosilamino-1-metil-2-metoxi-6-oxopirimidina con exceso de ClH.H2NOH permite aislar 5-E-aldoximino derivado como único producto. La estructura del mismo ha sido establecida en base a pruebas químicas y espectroscópicas

Estudio y caracterización de algunas 5-E-aldoximino-4-glucosilaminopirimidinas

La reacción de 1,6-dihidro-5-formil-4-β-D-(2 ', 3 ' 4 ', 6 '-tetra-O-acetil)-glucopiranosilamino-1-metil-2-metoxi-6-oxopirimidina con exceso de ClH.H2NOH permite aislar 5-E-aldoximino derivado como único producto. La estructura del mismo ha sido establecida en base a pruebas químicas y espectroscópicas.The reaction between 1,6-dihydro-S-formil-4- β -D-(tetra-O-acetyl}glucopyranosylamino-l-methyl-2-methoxy-6-oxo-pyrimidine and an excess of ClH.H2 NOH yields S-E-aldoximine derivative as the only producto On the basis of its chemical behaviour and espectroscopic data we propose its structure

First Dark Matter Results from the XENON100 Experiment

The XENON100 experiment, in operation at the Laboratori Nazionali del Gran Sasso in Italy, is designed to search for dark matter WIMPs scattering off 62 kg of liquid xenon in an ultra-low background dual-phase time projection chamber. In this letter, we present first dark matter results from the analysis of 11.17 live days of non-blind data, acquired in October and November 2009. In the selected fiducial target of 40 kg, and within the pre-defined signal region, we observe no events and hence exclude spin-independent WIMP-nucleon elastic scattering cross-sections above 3.4 x 10^-44 cm^2 for 55 GeV/c^2 WIMPs at 90% confidence level. Below 20 GeV/c^2, this result constrains the interpretation of the CoGeNT and DAMA signals as being due to spin-independent, elastic, light mass WIMP interactions.Comment: 5 pages, 5 figures. Matches published versio

The ArDM experiment

The aim of the ArDM project is the development and operation of a one ton double-phase liquid argon detector for direct Dark Matter searches. The detector measures both the scintillation light and the ionization charge from ionizing radiation using two independent readout systems. This paper briefly describes the detector concept and presents preliminary results from the ArDM R&D program, including a 3 l prototype developed to test the charge readout system.Comment: Proceedings of the Epiphany 2010 Conference, to be published in Acta Physica Polonica