98 research outputs found
Observation of Bell Inequality violation in B mesons
A pair of mesons from decay exhibit EPR type
non-local particle-antiparticle (flavor) correlation. It is possible to write
down Bell Inequality (in the CHSH form: ) to test the non-locality
assumption of EPR. Using semileptonic decays of at Belle
experiment, a clear violation of Bell Inequality in particle-antiparticle
correlation is observed:
S=2.725+-0.167(stat)+-0.092(syst)Comment: Conference Proceeding for Garda Lake Workshop 2003 "Mysteries,
Puzzles and Paradoxes in Quantum Mechanics
Polarization Correlations of 1S0 Proton Pairs as Tests of Bell and Wigner Inequalities
In an experiment designed to overcome the loophole of observer dependent
reality and satisfying the counterfactuality condition, we measured
polarization correlations of 1S0 proton pairs produced in 12C(d,2He) and
1H(d,He) reactions in one setting. The results of these measurements are used
to test the Bell and Wigner inequalties against the predictions of quantum
mechanics.Comment: 8 pages, 4 figure
Generation of Continuous Variable Einstein-Podolsky-Rosen Entanglement via the Kerr Nonlinearity in an Optical Fibre
We report on the generation of a continuous variable Einstein-Podolsky-Rosen
(EPR) entanglement using an optical fibre interferometer. The Kerr nonlinearity
in the fibre is exploited for the generation of two independent squeezed beams.
These interfere at a beam splitter and EPR entanglement is obtained between the
output beams. The correlation of the amplitude (phase) quadratures are measured
to be 4.0+-0.2 (4.0+-0.4) dB below the quantum noise limit. The sum criterion
for these squeezing variances 0.80+-0.03 < 2 verifies the nonseparability of
the state. The product of the inferred uncertainties for one beam 0.64+-0.08 is
well below the EPR limit of unity.Comment: RevTeX, 4 pages, 3 figures, to be published in Phys. Rev. Let
Long range absorption in the scattering of 6He on 208Pb and 197Au at 27 MeV
Quasi-elastic scattering of 6He at E_lab=27 MeV from 197Au has been measured
in the angular range of 6-72 degrees in the laboratory system employing LEDA
and LAMP detection systems. These data, along with previously analysed data of
6He + 208Pb at the same energy, are analyzed using Optical Model calculations.
The role of Coulomb dipole polarizability has been investigated. Large
imaginary diffuseness parameters are required to fit the data. This result is
an evidence for long range absorption mechanisms in 6He induced reactions.Comment: 10 pages, 10 figures, minor corrections. To appear in Nucl. Phys.
Runaway electron energy measurement using hard x-ray spectroscopy in "Damavand" tokamak
Set of experiments has been developed to study existing runaway electrons in "Damavand" tokamak plasma upon characteristics of hard x-ray emissions produced by collision of the runaway electrons with the plasma particles and limiters. As a first step, spatial distribution of hard x-ray emissions on the equatorial plane of the torus was considered. Obtained spectra of hard x-ray emissions for different alignments of shielded detector indicate isotropic emissivity in the equatorial plane. This is in agreement with wide angle cone of bremsstrahlung radiations, deduced from the mean value of energy of the runaway electrons. The mean energy was calculated from the slope of the energy spectrum of hard x-ray photons. In the second stage in order to investigate time evolution of energy of the runaway electrons, similar technique were applied to obtain hard x-ray energy in every 3 ms intervals, from the beginning to the end of plasma. The mean energy of the runaway electrons increases during the ramp up phase and reaches its maximum between 3 and 9 ms after plasma formation. Also considering the time dependence of the counted photons in each energy range shows that energetic photons are emitted during the ramp up phase of the plasma current in Damavand tokamak
Cooling the Collective Motion of Trapped Ions to Initialize a Quantum Register
We report preparation in the ground state of collective modes of motion of
two trapped 9Be+ ions. This is a crucial step towards realizing quantum logic
gates which can entangle the ions' internal electronic states. We find that
heating of the modes of relative ion motion is substantially suppressed
relative to that of the center-of-mass modes, suggesting the importance of
these modes in future experiments.Comment: 5 pages, including 3 figures. RevTeX. PDF and PostScript available at
http://www.bldrdoc.gov/timefreq/ion/qucomp/papers.htm . final (published)
version. Eq. 1 and Table 1 slightly different from original submissio
A compilation of charged-particle induced thermonuclear reaction rates
Low-energy cross section data for 86 charged-particle induced reactions involving light (1 less than or equal to Z less than or equal to 14), mostly stable, nuclei are compiled. The corresponding Maxwellian-averaged thermonuclear reaction rates of relevance in astrophysical plasmas at temperatures in the range from 10(6) K to 10(10) K are calculated. These evaluations assume either that the target nuclei are in their ground state, or that the target states are thermally populated following a Maxwell-Boltzmann distribution, except in some cases involving isomeric states. Adopted values complemented with lower and upper limits of the rates are presented in tabular form. Analytical approximations to the adopted rates, as well as to the inverse/direct rate ratios, are provided. (C) 1999 Elsevier Science B.V. All rights reserved
Matching of the H- beam to the low and medium energy section of the CERN Linac4
Linac4 is the near future 160 MeV H- linear accelerator of the CERN presently under construction. It will replace the present Linac2 as injector of the proton accelerator complex in CERN. The Linac4 is composed of a 45 keV ion source, a Low Energy Beam Transport (LEBT), a 352.2 MHz Radio Frequency Quadrupole (RFQ), which accelerates the beam to 3 MeV, and a Medium Energy Beam Transport (MEBT), housing a beam chopper, has been installed and commissioned in the Linac4 tunnel. The LEBT is composed of two solenoids and a diagnostic box; the MEBT is composed of three Radio Frequency (RF) cavities and 11 quadrupole magnets to match and transfer the beam from the source to the RFQ and DTL, respectively. In this paper, the beam matching process of the 45 keV H- beam to the RFQ and that of accelerated 3 MeV beam to the DTL has been presented. The MEBT beam commissioning was complemented with the emittance measurement of the DTL matched beam taken with a slit-and-grid emittance measurement device located after the MEBT line
 
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