46 research outputs found

    Non-Abelian (p,q) Strings in the Warped Deformed Conifold

    Get PDF
    We calculate the tension of (p,q)(p,q)-strings in the warped deformed conifold using the non-Abelian DBI action. In the large flux limit, we find exact agreement with the recent expression obtained by Firouzjahi, Leblond and Henry-Tye up to and including order 1/M21/M^2 terms if qq is also taken to be large. Furthermore using the finite qq prescription for the symmetrised trace operation we anticipate the most general expression for the tension valid for any (p,q)(p,q). We find that even in this instance, corrections to the tension scale as 1/M21/M^2 which is not consistent with simple Casimir scaling.Comment: 18 pages, Latex, 1 figure; Added a discussion of the case when the warp factor parameter b1b\neq 1 and typos correcte

    Unbounded violation of tripartite Bell inequalities

    Get PDF
    We prove that there are tripartite quantum states (constructed from random unitaries) that can lead to arbitrarily large violations of Bell inequalities for dichotomic observables. As a consequence these states can withstand an arbitrary amount of white noise before they admit a description within a local hidden variable model. This is in sharp contrast with the bipartite case, where all violations are bounded by Grothendieck's constant. We will discuss the possibility of determining the Hilbert space dimension from the obtained violation and comment on implications for communication complexity theory. Moreover, we show that the violation obtained from generalized GHZ states is always bounded so that, in contrast to many other contexts, GHZ states do in this case not lead to extremal quantum correlations. The results are based on tools from the theories of operator spaces and tensor norms which we exploit to prove the existence of bounded but not completely bounded trilinear forms from commutative C*-algebras.Comment: Substantial changes in the presentation to make the paper more accessible for a non-specialized reade

    Nuclear Alpha-Particle Condensates

    Full text link
    The α\alpha-particle condensate in nuclei is a novel state described by a product state of α\alpha's, all with their c.o.m. in the lowest 0S orbit. We demonstrate that a typical α\alpha-particle condensate is the Hoyle state (Ex=7.65E_{x}=7.65 MeV, 02+0^+_2 state in 12^{12}C), which plays a crucial role for the synthesis of 12^{12}C in the universe. The influence of antisymmentrization in the Hoyle state on the bosonic character of the α\alpha particle is discussed in detail. It is shown to be weak. The bosonic aspects in the Hoyle state, therefore, are predominant. It is conjectured that α\alpha-particle condensate states also exist in heavier nαn\alpha nuclei, like 16^{16}O, 20^{20}Ne, etc. For instance the 06+0^+_6 state of 16^{16}O at Ex=15.1E_{x}=15.1 MeV is identified from a theoretical analysis as being a strong candidate of a 4α4\alpha condensate. The calculated small width (34 keV) of 06+0^+_6, consistent with data, lends credit to the existence of heavier Hoyle-analogue states. In non-self-conjugated nuclei such as 11^{11}B and 13^{13}C, we discuss candidates for the product states of clusters, composed of α\alpha's, triton's, and neutrons etc. The relationship of α\alpha-particle condensation in finite nuclei to quartetting in symmetric nuclear matter is investigated with the help of an in-medium modified four-nucleon equation. A nonlinear order parameter equation for quartet condensation is derived and solved for α\alpha particle condensation in infinite nuclear matter. The strong qualitative difference with the pairing case is pointed out.Comment: 71 pages, 41 figures, review article, to be published in "Cluster in Nuclei (Lecture Notes in Physics) - Vol.2 -", ed. by C. Beck, (Springer-Verlag, Berlin, 2011

    Measurement of the Positive Muon Anomalous Magnetic Moment to 0.46 ppm

    Get PDF
    We present the first results of the Fermilab Muon g-2 Experiment for the positive muon magnetic anomaly aμ(gμ2)/2a_\mu \equiv (g_\mu-2)/2. The anomaly is determined from the precision measurements of two angular frequencies. Intensity variation of high-energy positrons from muon decays directly encodes the difference frequency ωa\omega_a between the spin-precession and cyclotron frequencies for polarized muons in a magnetic storage ring. The storage ring magnetic field is measured using nuclear magnetic resonance probes calibrated in terms of the equivalent proton spin precession frequency ω~p{\tilde{\omega}'^{}_p} in a spherical water sample at 34.7^{\circ}C. The ratio ωa/ω~p\omega_a / {\tilde{\omega}'^{}_p}, together with known fundamental constants, determines aμ(FNAL)=116592040(54)×1011a_\mu({\rm FNAL}) = 116\,592\,040(54)\times 10^{-11} (0.46\,ppm). The result is 3.3 standard deviations greater than the standard model prediction and is in excellent agreement with the previous Brookhaven National Laboratory (BNL) E821 measurement. After combination with previous measurements of both μ+\mu^+ and μ\mu^-, the new experimental average of aμ(Exp)=116592061(41)×1011a_\mu({\rm Exp}) = 116\,592\,061(41)\times 10^{-11} (0.35\,ppm) increases the tension between experiment and theory to 4.2 standard deviationsComment: 10 pages; 4 figure

    The Physics of the B Factories

    Get PDF

    Glancing angle X-ray absorption spectroscopy to investigate changes in the local atomic structure around uranium in leached glasses

    No full text
    SIGLEAvailable from British Library Document Supply Centre- DSC:DX83542 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

    DEPTH CONTROLLED EXAFS AND NEAR EDGE SPECTROSCOPY TO STUDY SURFACE LAYER STRUCTURE

    No full text
    Calculated and experimental intensity values are presented and compared for EXAFS spectrometry at grazing incidence with fluorescence or reflectivity detection, and samples in the form of single or double metal films evaporated onto flat glass substrates

    GRAZING INCIDENCE FLUORESCENCE EXAFS AND NEAR EDGE SPECTROSCOPY FOR CORRODED GLASS SURFACES

    No full text
    EXAFS at grazing incidence with fluorescence detection has been used to investigate the local atomic structure around uranium at the surface of borosilicate glasses. Structural changes have been observed as a result of leaching in water at 100°C. These indicate that uranium migrates to the surface to form island structures in a surface layer which, subsequently, peels off to reveal fresh surface for further corrosion

    Surface core level spectroscopy of the Pt25Co75 (110) and (100) alloy surfaces

    No full text
    Core level photoemission spectroscopy of the Pt 4f7/2 level is used to investigate the surface and bulk Pt environments in the disordered alloy Pt25Co75. For the (110) face no Pt is observed at the surface, and only a single Pt bulk site is identified with a chemical shift of 250meV. For the denser (100) face the same bulk site is observed together with a surface peak, corresponding to a surface layer with Pt enrichment. The chemical shift at the surface is weaker than in the bulk
    corecore