18 research outputs found

    QKD in Standard Optical Telecommunications Networks

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    To perform Quantum Key Distribution, the mastering of the extremely weak signals carried by the quantum channel is required. Transporting these signals without disturbance is customarily done by isolating the quantum channel from any noise sources using a dedicated physical channel. However, to really profit from this technology, a full integration with conventional network technologies would be highly desirable. Trying to use single photon signals with others that carry an average power many orders of magnitude bigger while sharing as much infrastructure with a conventional network as possible brings obvious problems. The purpose of the present paper is to report our efforts in researching the limits of the integration of QKD in modern optical networks scenarios. We have built a full metropolitan area network testbed comprising a backbone and an access network. The emphasis is put in using as much as possible the same industrial grade technology that is actually used in already installed networks, in order to understand the throughput, limits and cost of deploying QKD in a real network

    The 8 Be scattering system in the framework of a microscopic theory

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    We present conclusions for the 8 Be scattering system from a multi-channel calculation in the framework of a microscopic nuclear cluster model. The energy region from α-α threshold up to 30 MeV center of mass is investigated; results of an eigenphase analysis for J π -values from 0 + to 4 + and 0 − to 4 − are displayed. For comparison and completion we have performed quasibound state calculations taking into account possible combinations of participating structures. The results throw light upon a complicated sequence of resonant states and moreover predict the occurrence of some additional levels in the energy spectrum.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45823/1/10050_2005_Article_BF01408973.pd

    Measurement of \chi_{c2} Production in Two-Photon Collisions

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    The production of the \chi_{c2} charmonium state in two-photon collisions has been measured with the Belle detector at the KEKB e^+e^- collider. A clear signal for \chi_{c2} --> \gamma J/\psi, J/\psi --> l^+l^- is observed in a 32.6fb^{-1} data sample accumulated at center-of-mass energies near 10.6GeV, and the product of its two-photon decay width and branching fraction is determined to be \Gamma_{\gamma\gamma}(\chi_{c2})B(\chi_{c2} --> \gamma J/\psi) B(J/\psi --> l^+l^-)= 13.5 +/- 1.3(stat.) +/- 1.1(syst.)eV.Comment: 16 pages, 5 figures, to be submitted to Phys. Lett.
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