1,630 research outputs found

    Forward-rapidity azimuthal and radial flow of identified particles for sNN\sqrt{s_{NN}} = 200 GeV Au+Au collisions

    Full text link
    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 (v2(pT)v_{2}(p_{T})) of the azimuthal angular distribution. We report on a measurement of identified-particle v2v_{2} as a function of pTp_{T} (0.5-2.0 GeV/c), centrality (0-25%, 25-50%), and pseudorapidity (0η<3.20\leq\eta<3.2) for sNN=200GeV\sqrt{s_{NN}} = 200 \rm GeV Au+Au collisions. The BRAHMS spectrometers are used for particle identification (π\pi, 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

    Full text link
    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 16^{16}O + 27^{27}Al at Elab_{lab}=116 MeV

    Full text link
    The inclusive energy distributions of fragments (3\leqZ\leq7) emitted in the reaction 16^{16}O + 27^{27}Al at Elab=E_{lab} = 116 MeV have been measured in the angular range θlab\theta_{lab} = 15^\circ - 115^\circ. 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 (15×1022\sim 1 - 5\times 10^{-22} 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

    Full text link
    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 2\sqrt{2}. The result that the entanglement is one bit when the relative phase between the composing states is π\pi 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

    Get PDF
    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

    Get PDF
    The dynamics of the entanglement for coherent excitonic states in the system of two coupled large semiconductor quantum dots (R/aB1R/a_{B}\gg 1) 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

    Get PDF
    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
    corecore