758 research outputs found

    Topology, chiral and screening transitions at finite density in two colour QCD

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    The behaviour of the topological susceptibility in QCD with two colours and 8 flavours of quarks is studied at nonzero temperature on the lattice across the finite density transition. It is shown that its signal drops at a (pseudo-)critical chemical potential mu_c. The Polyakov loop and the chiral condensate undergo their transitions at the same value. Pauli blocking supervenes at a value of the chemical potential larger than mu_c.Comment: Latex file (uses espcrc2.sty), 4 pages, 4 ps figures; talk presented at QCD-06, Montpellier, July 200

    Vector spectrum and color screening in two color QCD at nonzero T and \mu

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    We discuss a few aspects of the phase diagram of two color lattice QCD: we investigate the long distance screening analyzing the behavior of the interquark potential at large distances; we present a first set of results for vector mesons and diquarks; we note similarities and differences between features at high temperature and high baryon density.Comment: 9 pages, 4 figures; talk at the GISELDA Meeting held in Frascati, Italy, 14-18 January 200

    Spin susceptibility of the superfluid 3^{3}He-B in aerogel

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    The temperature dependence of paramagnetic susceptibility of the superfluid ^{3}He-B in aerogel is found. Calculations have been performed for an arbitrary phase shift of s-wave scattering in the framework of BCS weak coupling theory and the simplest model of aerogel as an aggregate of homogeneously distributed ordinary impurities. Both limiting cases of the Born and unitary scattering can be easily obtained from the general result. The existence of gapless superfluidity starting at the critical impurity concentration depending on the value of the scattering phase has been demonstrated. While larger than in the bulk liquid the calculated susceptibility of the B-phase in aerogel proves to be conspicuously smaller than that determined experimentally in the high pressure region.Comment: 10 pages, 4 figures, REVTe

    Efeito da altura do resíduo sobre a produção e a estrutura de sorgo forrageiro.

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    O cultivo de sorgo forrageiro (Sorghum bicolor (L.) Moench.) tem crescido na região Noroeste do Rio Grande do Sul nos últimos anos. Os produtores rurais estão sendo orientados a manejar o sorgo forrageiro em pastejo rotacionado, respeitando uma altura de entrada dos animais acima de 70 cm e altura de saída (resíduo) em torno de apenas 5 cm.bitstream/item/63868/1/BP31.pd

    A new Architecture for High Speed, Low Latency NB-LDPC Check Node Processing

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    International audience—Non-binary low-density parity-check codes have superior communications performance compared to their binary counterparts. However, to be an option for future standards, efficient hardware architectures must be developed. State-of-the-art decoding algorithms lead to architectures suffering from low throughput and high latency. The check node function accounts for the largest part of the decoders overall complexity. In this paper a new hardware aware check node algorithm and its architecture is proposed. It has state-of-the-art communications performance while reducing the decoding complexity. The presented architecture has a 14 times higher area efficiency, increases the energy efficiency by factor 2.5 and reduces the latency by factor of 3.5 compared to a state-of-the-art architecture

    Effective Hamiltonian Approach to Hyperon Beta Decay with Final-State Baryon Polarization

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    Using an effective Hamiltonian approach, we obtain expressions for hyperon beta decay final-state baryon polarization. Terms through second order in the energy release are retained. The resulting approximate expressions are much simpler and more compact than the exact expressions, and they agree closely with them.Comment: 1 Figure Will appear in Phys Rev D 60 Article 117505 (Dec 1, 1999

    Cooled video camera for optical investigations below 1 mK

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    An optical imaging system for milliKelvin temperatures has been developed based on a regular B/W surveillance camera (25 frames/s), with its CCD sensor inside the 4‐K vacuum can of our nuclear demagnetization cryostat. The heat leak to the nuclear stage, caused by the operation of the video camera, was reduced below 1 nW by careful rf shielding. The construction of the system and its limits of operation are discussed.Peer reviewe

    Wetting of Superfluid 4He by Liquid 3He

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    We have investigated optically the spreading of He3 on top of the He4-rich solution in phase-separated helium-mixture films, 20-50 μm thick. In equilibrium, the He3 layer wets the He4-rich phase completely, but nearly circular or stripelike pools of He3-rich phase are stabilized instead when He4 atoms are condensed to the liquid sample at the rate 10 exp 15-5 × 10 exp 15 atoms/cm2s. For the contact angle we obtain about 10 mrad, which suggests a fractional change of the He3 surface tension by a factor of 10 exp −5 from the equilibrium value.Peer reviewe
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