72,514 research outputs found

    Heavy Quarkonium

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    I review heavy quarkonium physics in view of recent experimental results. In particular, I discuss new results on spin singlet states, photon and hadronic transitions, D-states and discovery of yet unexplained narrow X(3872) state.Comment: 15 pages, 16 figures. 2nd version: minor changes in references and text. Invited talk presented at the 21st International Symposium On Lepton And Photon Interactions At High Energies (LP03) 11-16 August 2003, Batavia, Illinoi

    A two component jet model for the X-ray afterglow flat segment in short GRB 051221A

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    In the double neutron star merger or neutron star-black hole merger model for short GRBs, the outflow launched might be mildly magnetized and neutron rich. The magnetized neutron-rich outflow will be accelerated by the magnetic and thermal pressure and may form a two component jet finally, as suggested by Vlahakis, Peng & K\"{o}nigl (2003). We show in this work that such a two component jet model could well reproduce the multi-wavelength afterglow lightcurves, in particular the X-ray flat segment, of short GRB 051221A. In this model, the central engine need not to be active much longer than the prompt γ\gamma-ray emission.Comment: 11 pages, 2 figure; Accepted for publication by ApJ

    Notes on highest weight modules of the elliptic algebra Aq,p(sl^2){\cal A}_{q,p}\left(\widehat{sl}_2\right)

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    We discuss a construction of highest weight modules for the recently defined elliptic algebra Aq,p(sl^2){\cal A}_{q,p}(\widehat{sl}_2), and make several conjectures concerning them. The modules are generated by the action of the components of the operator LL on the highest weight vectors. We introduce the vertex operators Φ\Phi and Ψ\Psi^* through their commutation relations with the LL-operator. We present ordering rules for the LL- and Φ\Phi-operators and find an upper bound for the number of linearly independent vectors generated by them, which agrees with the known characters of sl^2\widehat{sl}_2-modules.Comment: Nonstandard macro package eliminate

    Probabilistic teleportation of unknown two-particle state via POVM

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    We propose a scheme for probabilistic teleportation of unknown two-particle state with partly entangled four-particle state via POVM. In this scheme the teleportation of unknown two-particle state can be realized with certain probability by performing two Bell state measurements, a proper POVM and a unitary transformation.Comment: 5 pages, no figur

    Poly(acrylic acid)-coated iron oxide nanoparticles : quantitative evaluation of the coating properties and applications for the removal of a pollutant dye

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    In this work, 6 to 12 nm iron oxide nanoparticles were synthesized and coated with poly(acrylic acid) chains of molecular weight 2100 g/mol. Based on a quantitative evaluation of the dispersions, the bare and coated particles were thoroughly characterized. The number densities of polymers adsorbed at the particle surface and of available chargeable groups were found to be 1.9 +/- 0.3 nm-2 and 26 +/- 4 nm-2, respectively. Occurring via a multi-site binding mechanism, the electrostatic coupling leads to a solid and resilient anchoring of the chains. To assess the efficacy of the particles for pollutant remediation, the adsorption isotherm of methylene blue molecules, a model of pollutant, was determined. The excellent agreement between the predicted and measured amounts of adsorbed dyes suggests that most carboxylates participate to the complexation and adsorption mechanisms. An adsorption of 830 mg/g was obtained. This quantity compares well with the highest values available for this dye.Comment: 14 pages 5 figures, accepted 06-Dec-2012; Journal of Colloid and Interface Science (2013

    Spontaneous Relaxation of a Charge Qubit under Electrical Measurement

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    In this work we first derive a generalized conditional master equation for quantum measurement by a mesoscopic detector, then study the readout characteristics of qubit measurement where a number of new features are found. The work would in particular highlight the qubit spontaneous relaxation effect induced by the measurement itself rather than an external thermal bath.Comment: 4 pages, 2 figures; an error in Eq.(8) is correcte

    Optimal Controlled Teleportation

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    We give the analytic expressions of maximal probabilities of successfully controlled teleportating an unknown qubit via every kind of tripartite states. Besides, another kind of localizable entanglement is also determined. Furthermore, we give the sufficient and necessary condition that a three-qubit state can be collapsed to an EPR pair by a measurement on one qubit, and characterize the three-qubit states that can be used as quantum channel for controlled teleporting a qubit of unknown information with unit probability and with unit fidelity.Comment: 4 page

    Antilocalization of Coulomb Blockade in a Ge-Si Nanowire

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    The distribution of Coulomb blockade peak heights as a function of magnetic field is investigated experimentally in a Ge-Si nanowire quantum dot. Strong spin-orbit coupling in this hole-gas system leads to antilocalization of Coulomb blockade peaks, consistent with theory. In particular, the peak height distribution has its maximum away from zero at zero magnetic field, with an average that decreases with increasing field. Magnetoconductance in the open-wire regime places a bound on the spin-orbit length (lsol_{so} < 20 nm), consistent with values extracted in the Coulomb blockade regime (lsol_{so} < 25 nm).Comment: Supplementary Information available at http://bit.ly/19pMpd
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