1111688
Alternative energy estimation from the shower lateral distribution function
The surface detector technique has been successfully used to detect cosmic ray showers for several decades. Scintillators or Cerenkov water tanks can be used to measure the number of particles and/or the energy density at a given depth in the atmosphere and reconstruct the primary particle properties. It has been shown that the experiment configuration and the resolution in reconstr ucting the core position determine a distance to the shower axis at which the lateral distribution function (LDF) of particles shows the least variation with respect to different primary particles type, simulation models and specific shapes of the LDF. Therefore, the signal at this distance (600 m for Haverah Park and 1000 m for Auger Observatory) has shown to be a good estimator of the shower energy. Revisiting the above technique, we show that a range of distances to the shower axis, instead of one single point, can be used as estimator of the shower energy. A comparison is done for the Auger Observatory configuration and the new estimator proposed he re is shown to be a good and robust alternative to the standard single point procedure.
28707884
New values for neutrino masses in the context of a horizontal model.
We study in detail an extended version of the Glashow-Salam-Weinberg model for the electroweak interactions. It has an extra global horizontal symmetry, which allows the appearance of neutrino mass terms. The constraints imposed by the standard cosmological model are used to determine the allowed range of variation of the free parameters of this model. We find that unstable massive neutrinos are permitted in a set of values for their masses between 100 eV and --1 GeV.
17220930
Optimal filters for the detection of continuous gravitational waves
We determine the transfer functions of two kinds of filters that can be used in the detection of continuous gravitational radiation. The first one optimizes the signal-to-noise ratio, and the second reproduces the wave with minimum error. We analyse the behaviour of these filters in connection with actual detection schemes.
109078723
Lining material tests for the AUGER PROJECT surface detector
We are trying to obtain a suitable material to compose the lining of a water Cerenkov tank for the surface detector. part of a hybrid detector of the Auger Project. Results of tests were compared with DuPont 1073Tyvek TM and obtained a reasonable performance for (PVC+BaSO 4 ) material.
119431516
Entanglement versus chaos in disordered spin chains
We use a Heisenberg spin-1/2 chain to investigate how chaos and localization may affect the entanglement of pairs of qubits. To measure how much entangled a pair is, we compute its concurrence, which is then analyzed in the delocalized (localized) and in the chaotic (nonchaotic) regimes. Our results indicate that chaos reduces entanglement and that entanglement decreases in the region of strong localization. In the transition region from a chaotic to a nonchaotic regime localization increases entanglement. We also show that entanglement is larger for strongly interacting qubits (nearest neighbors) than for weakly interacting qubits (next and next-next neighbors)
118704565
X versus y scaling in nonrelativistic deep inelastic scattering
55062742
Laser tests of silicon detectors
This paper collects experiences from the development of a silicon sensor laser testing setup and from tests of silicon strip modules (ATLAS End-cap SCT), pixel modules (DEPFET) and large-area diodes using semiconductor lasers. Lasers of 1060 and 680 nm wavelengths were used. A sophisticated method of focusing the laser was developed. Timing and interstrip properties of modules were measured. Analysis of optical effects involved and detailed discussion about the usability of laser testing for particle detectors are presented.