1,710 research outputs found
Forward-rapidity azimuthal and radial flow of identified particles for = 200 GeV Au+Au collisions
A strong azimuthal flow signature at RHIC suggests rapid system equilibration
leading to an almost perfect fluid state. The longitudinal extent of the flow
behavior depends on how this state is formed and can be studied by measuring
the pseudorapidity and transverse momentum dependence of the second Fourier
component () of the azimuthal angular distribution. We report on
a measurement of identified-particle as a function of (0.5-2.0
GeV/c), centrality (0-25%, 25-50%), and pseudorapidity () for
Au+Au collisions. The BRAHMS spectrometers are
used for particle identification (, K, p) and momentum determination and
the BRAHMS global detectors are used to determine the corresponding
reaction-plane angles. The results are discussed in terms of the rapidity
dependence of constituent quark scaling and in terms of models that develop the
complete (azimuthal and radial) hydrodynamic aspects of the forward dynamics at
RHIC.Comment: 4 pages, 4 figures - To appear in the conference proceedings for
Quark Matter 2009, March 30-April 4, Knoxville, Tennesse
Continuous-variable quantum teleportation of entanglement
Entangled coherent states can be used to determine the entanglement fidelity
for a device that is designed to teleport coherent states. This entanglement
fidelity is universal, in that the calculation is independent of the use of
entangled coherent states and applies generally to the teleportation of
entanglement using coherent states. The average fidelity is shown to be a poor
indicator of the capability of teleporting entanglement; i.e., very high
average fidelity for the quantum teleportation apparatus can still result in
low entanglement fidelity for one mode of the two-mode entangled coherent
state.Comment: 5 pages, 1 figure, published versio
Dissipative collisions in O + Al at E=116 MeV
The inclusive energy distributions of fragments (3Z7) emitted in
the reaction O + Al at 116 MeV have been measured in
the angular range = 15 - 115. A non-linear
optimisation procedure using multiple Gaussian distribution functions has been
proposed to extract the fusion-fission and deep inelastic components of the
fragment emission from the experimental data. The angular distributions of the
fragments, thus obtained, from the deep inelastic component are found to fall
off faster than those from the fusion-fission component, indicating shorter
life times of the emitting di-nuclear systems. The life times of the
intermediate di-nuclear configurations have been estimated using a diffractive
Regge-pole model. The life times thus extracted (
Sec.) are found to decrease with the increase in the fragment charge. Optimum
Q-values are also found to increase with increasing charge transfer i.e. with
the decrease in fragment charge.Comment: 9 pages, 4 figures, 1 tabl
Entanglement in bipartite generalized coherent states
Entanglement in a class of bipartite generalized coherent states is
discussed. It is shown that a positive parameter can be associated with the
bipartite generalized coherent states so that the states with equal value for
the parameter are of equal entanglement. It is shown that the maximum possible
entanglement of 1 bit is attained if the positive parameter equals .
The result that the entanglement is one bit when the relative phase between the
composing states is in bipartite coherent states is shown to be true for
the class of bipartite generalized coherent states considered.Comment: 10 pages, 4 figures; typos corrected and figures redrawn for better
clarit
Towards high-resolution flow cameras made of artificial hair flow-sensors for flow pattern recognition
Next to image sensors, future’s robots will definitely use a variety of sensing mechanisms for navigation and prevention of risks to human life, for example flow-sensor arrays for 3D hydrodynamic reconstruction of the near environment. This paper aims to quantify the possibilities of our artificial hair flow-sensor for high-resolution flow field visualization. Using silicon-on-insulator (SOI) technology with deep trench isolation structures, hair-based flow sensors with separate electrodes arranged in wafer-scale arrays have been successfully fabricated. Frequency Division Multiplexing (FDM) is used to interrogate individual hair elements providing simultaneous real-time flow measurements from multiple hairs. This is demonstrated by reconstructing the dipole fields along different array elements and hence localizing a dipole source relative to the hair array elements
Dynamics of entanglement for coherent excitonic states in a system of two coupled quantum dots and cavity QED
The dynamics of the entanglement for coherent excitonic states in the system
of two coupled large semiconductor quantum dots () mediated by a
single-mode cavity field is investigated. Maximally entangled coherent
excitonic states can be generated by cavity field initially prepared in odd
coherent state. The entanglement of the excitonic coherent states between two
dots reaches maximum when no photon is detected in the cavity. The effects of
the zero-temperature environment on the entanglement of excitonic coherent
state are also studied using the concurrence for two subsystems of the excitonsComment: 7 pages, 6 figure
Ni64 +92Zr fission yields at energies close to the Coulomb barrier
Fission yields for the Zr64 reaction at laboratory energies between 240 and 300 MeV have been measured. Elastic scattering angular distributions were also obtained and used to deduce the generalized total reaction cross sections. The competition between fission and light-particle evaporation from the compound nucleus is well reproduced by statistical-model calculations. However, the calculated neutron multiplicities for this reaction are larger than those previously measured. Possible reasons for this discrepancy are discussed
- …