4,328 research outputs found
Bell inequality violation by entangled single photon states generated from a laser, a LED or a Halogen lamp
In single-particle or intraparticle entanglement, two degrees of freedom of a
single particle, e.g., momentum and polarization of a single photon, are
entangled. Single-particle entanglement (SPE) provides a source of non
classical correlations which can be exploited both in quantum communication
protocols and in experimental tests of noncontextuality based on the
Kochen-Specker theorem. Furthermore, SPE is robust under decoherence phenomena.
Here, we show that single-particle entangled states of single photons can be
produced from attenuated sources of light, even classical ones. To
experimentally certify the entanglement, we perform a Bell test, observing a
violation of the Clauser, Horne, Shimony and Holt (CHSH) inequality. On the one
hand, we show that this entanglement can be achieved even in a classical light
beam, provided that first-order coherence is maintained between the degrees of
freedom involved in the entanglement. On the other hand, we prove that filtered
and attenuated light sources provide a flux of independent SPE photons that,
from a statistical point of view, are indistinguishable from those generated by
a single photon source. This has important consequences, since it demonstrates
that cheap, compact, and low power entangled photon sources can be used for a
range of quantum technology applications
XQCAT: eXtra Quark Combined Analysis Tool
XQCAT (eXtra Quark Combined Analysis Tool) is a tool aimed at determining
exclusion confidence levels for scenarios of new physics characterised by the
presence of one or multiple heavy extra quarks which interact through Yukawa
couplings with any of the Standard Model quarks. The code uses a database of
efficiencies for pre-simulated processes of QCD-induced pair production of
extra quarks and their subsequent on-shell decays. In the version 1.2 of XQCAT
the efficiencies have been computed for a set of seven publicly available
search results by the CMS experiment. The input for the code is a text file in
which masses, branching ratios and dominant chirality of the couplings of the
new quarks are provided. The output of the code is the exclusion confidence
levels of the test point for each implemented experimental analysis considered
individually and, when possible, in statistical combination.Comment: 18 pages, 2 figures, version accepted for publication in Comp. Phys.
Comm., fixed formatting problems caused by the arXiv's autotex syste
Classificadora de cilindros divergentes para tomate de mesa: uma alternativa para pequenos produtores.
bitstream/CNPDIA-2010/12616/1/DOC46-2009.pd
The BMW (Brera-Multiscale-Wavelet) Catalogue of Serendipitous X-ray Sources
In collaboration with the Observatories of Palermo and Rome and the SAX-SDC
we are constructing a multi-site interactive archive system featuring specific
analysis tools. In this context we developed a detection algorithm based on the
Wavelet Transform (WT) and performed a systematic analysis of all ROSAT-HRI
public data (~3100 observations +1000 to come). The WT is specifically suitable
to detect and characterize extended sources while properly detecting point
sources in very crowded fields. Moreover, the good angular resolution of HRI
images allows the source extension and position to be accurately determined.
This effort has produced the BMW (Brera Multiscale Wavelet) catalogue, with
more than 19,000 sources detected at the 4.2 sigma level. For each source
detection we have information on the X-ray flux and extension, allowing for
instance to select complete samples of extended X-ray sources such as candidate
clusters of galaxies or SNR's. Here we present an overview of first results
from several undergoing projects which make use of the BMW catalogue.Comment: 7 pages, 6 postscript files, 2 gif images, to appear in the
proceedings of the conference "Mining the Sky", August 2000, Garching,
German
Atividade respiratória de pimentas durante o armazenamento.
bitstream/CNPH-2009/33384/1/bpd_33.pd
Modified Atmosphere Packaging for Perishable Plant Products
Modified atmosphere packaging. Passive. Active. O² and CO² limits. Types of plastic films used in MAP. Package parameters. Respiration rate. Temperature. Permeability. Respiration rats messurement. Plant responses of MAP
The BMW Deep X-ray Cluster Survey
We briefly describe the main features of the Brera Multi-Wavelet (BMW) survey
of serendipitous X-ray clusters, based on the still unexploited ROSAT-HRI
archival observations. Cluster candidates are selected from the general BMW
catalogue of 20,000 sources based exclusively on their X-ray extension.
Contrary to common wisdom, a clever selection of the HRI energy channels allows
us to significantly reduce the background noise, thus greatly improving the
ability to detect low surface-brightness sources as clusters. The resulting
sample of ~250 candidates shows a very good sky coverage down to a flux
\~3x10^-14 erg/s/cm^2 ([0.5-2.0] keV band), i.e comparable to existing
PSPC-based deep survey, with a particularly interesting area of ~100 sq.deg.
around fluxes ~10^-13 erg/s/cm^2, i.e. where highly-luminous, rare systems at
z~0.6-1 can be detected. At the same time, the superior angular resolution of
the instrument should avoid biases against intrinsically small systems, while
easing the identification process (e.g. by spotting blends and AGN
contaminants). While about 20% of the candidates are already identified with
groups/clusters at z<0.3 on the DSS2 images, we have started a deep CCD imaging
campaign to observe all sources associated to "blank fields". First results
from these observations reveal a distant (z>0.5) bonafide cluster counterpart
for ~80% of the targets.Comment: 3 pages, 2 figures; to appear in Proc. of the ESO/ECF/STSCI workshop
on "Deep Fields", Garching Oct 2000, (Publ: Springer
- …