2,272 research outputs found
An effectual template bank for the detection of gravitational waves from inspiralling compact binaries with generic spins
We report the construction of a three-dimensional template bank for the
search for gravitational waves from inspiralling binaries consisting of
spinning compact objects. The parameter space consists of two dimensions
describing the mass parameters and one "reduced-spin" parameter, which
describes the secular (non-precessing) spin effects in the waveform. The
template placement is based on an efficient stochastic algorithm and makes use
of the semi-analytical computation of a metric in the parameter space. We
demonstrate that for "low-mass" () binaries,
this template bank achieves effective fitting factors --
towards signals from generic spinning binaries in the advanced detector era
over the entire parameter space of interest (including binary neutron stars,
binary black holes, and black hole-neutron star binaries). This provides a
powerful and viable method for searching for gravitational waves from generic
spinning low-mass compact binaries. Under the assumption that spin magnitudes
of black-holes [neutron-stars] are uniformly distributed between 0--0.98 [0 --
0.4] and spin angles are isotropically distributed, the expected improvement in
the average detection volume (at a fixed signal-to-noise-ratio threshold) of a
search using this reduced-spin bank is , as compared to a search
using a non-spinning bank.Comment: Minor changes, version appeared in Phys. Rev.
Detection of ultra-high energy cosmic ray showers with a single-pixel fluorescence telescope
We present a concept for large-area, low-cost detection of ultra-high energy
cosmic rays (UHECRs) with a Fluorescence detector Array of Single-pixel
Telescopes (FAST), addressing the requirements for the next generation of UHECR
experiments. In the FAST design, a large field of view is covered by a few
pixels at the focal plane of a mirror or Fresnel lens. We report first results
of a FAST prototype installed at the Telescope Array site, consisting of a
single 200 mm photomultiplier tube at the focal plane of a 1 m Fresnel lens
system taken from the prototype of the JEM-EUSO experiment. The FAST prototype
took data for 19 nights, demonstrating remarkable operational stability. We
detected laser shots at distances of several kilometres as well as 16 highly
significant UHECR shower candidates.Comment: Accepted for publication in Astroparticle Physic
Optical Relative Calibration and Stability Monitoring for the Auger Fluorescence Detector
The stability of the fluorescence telescopes of the Pierre Auger Observatory
is monitored with the optical relative calibration setup. Optical fibers
distribute light pulses to three different diffuser groups within the optical
system. The total charge per pulse is measured for each pixel and compared with
reference calibration measurements. This allows monitoring the short and long
term stability with respect of the relative timing between pixels and the
relative gain for each pixel. The designs of the LED calibration unit (LCU) and
of the Xenon flash lamp used for relative calibration, are described and their
capabilities to monitor the stability of the telescope performances are
studied. We report the analysis of relative calibration data recorded during
2004. Fluctuations in the relative calibration constants provide a measure of
the stability of the FD.Comment: 4 pp. To appear in the proceedings of 29th International Cosmic Ray
Conference (ICRC 2005), Pune, India, 3-11 Aug 200
Search for microwave emission from ultrahigh energy cosmic rays
We present a search for microwave emission from air showers induced by
ultrahigh energy cosmic rays with the microwave detection of air showers
experiment. No events were found, ruling out a wide range of power flux and
coherence of the putative emission, including those suggested by recent
laboratory measurements.Comment: 5 pages, 3 figure
Review of recent experimental progresses in Foundations of Quantum Mechanics and Quantum Information obtained in Parametric Down Conversion Experiments at IENGF
We review some recent experimental progresses concerning Foundations of
Quantum Mechanics and Quantum Information obtained in Quantum Optics Laboratory
"Carlo Novero" at IENGF.
More in details, after a short presentation of our polarization entangled
photons source (based on precise superposition of two Type I PDC emission) and
of the results obtained with it, we describe an innovative double slit
experiment where two degenerate photons produced by PDC are sent each to a
specific slit. Beyond representing an interesting example of relation between
visibility of interference and "welcher weg" knowledge, this configuration has
been suggested for testing de Broglie-Bohm theory against Standard Quantum
Mechanics. Our results perfectly fit SQM results, but disagree with dBB
predictions.
Then, we discuss a recent experiment addressed to clarify the issue of which
wave-particle observables are really to be considered when discussing wave
particle duality. This experiments realises the Agarwal et al. theoretical
proposal, overcoming limitations of a former experiment.
Finally, we hint to the realization of a high-intensity
high-spectral-selected PDC source to be used for quantum information studies
The MIDAS experiment: A prototype for the microwave emission of Ultra-High Energy Cosmic Rays
Recent measurements suggest that extensive air showers initiated by
ultra-high energy cosmic rays (UHECR) emit signals in the microwave band of the
electromagnetic spectrum caused by the collisions of the free-electrons with
the atmospheric neutral molecules in the plasma produced by the passage of the
shower. Such emission is isotropic and could allow the detection of air showers
with 100% duty cycle and a calorimetric-like energy measurement, a significant
improvement over current detection techniques. We have built MIDAS (MIcrowave
Detection of Air Showers), a prototype of microwave detector, which consists of
a 4.5 m diameter antenna with a cluster of 53 feed-horns in the 4 GHz range.
The details of the prototype and first results will be presented.Comment: To appear in the proceedings of 12th Topical Seminar on Innovative
Particle and Radiation Detectors (IPRD10), Siena, Italy, 7 - 10 June 201
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