256,043 research outputs found

    Rotating Superconductors and the Frame-independent London Equation

    Full text link
    A frame-independent, thermodynamically exact London equation is presented, which is especially valid for rotating superconductors. A direct result is the unexpectedly high accuracy (∼10−10\sim10^{-10}) for the usual expression of the London moment.Comment: 4 pages, 0 figure

    Gauge Invariance of the Muonium-Antimuonium Oscillation Time Scale and Limits on Right-Handed Neutrino Masses

    Full text link
    The gauge invariance of the muonium-antimuonium (MMˉM\bar{M}) oscillation time scale is explicitly demonstrated in the Standard Model modified only by the inclusion of singlet right-handed neutrinos and allowing for general renormalizable interactions. The see-saw mechanism is exploited resulting in three light Majorana neutrinos and three heavy Majorana neutrinos with mass scale MR≫MWM_R\gg M_W. The leading order matrix element contribution to the MMˉM\bar{M} oscillation process is computed in RξR_\xi gauge and shown to be ξ\xi independent thereby establishing the gauge invariance to this order. Present experimental limits resulting from the non-observation of the oscillation process sets a lower limit on MRM_R roughly of order 600 GeV.Comment: 17 pages, 6 figures, Late

    A Lattice Study of the Glueball Spectrum

    Full text link
    Glueball spectrum is studied using an improved gluonic action on asymmetric lattices in the pure SU(3) gauge theory. The smallest spatial lattice spacing is about 0.08fm0.08fm which makes the extrapolation to the continuum limit more reliable. In particular, attention is paid to the scalar glueball mass which is known to have problems in the extrapolation. Converting our lattice results to physical units using the scale set by the static quark potential, we obtain the following results for the glueball masses: MG(0++)=1730(90)MeVM_G(0^{++})=1730(90)MeV for the scalar glueball mass and MG(2++)=2400(95)MeVM_G(2^{++})=2400(95)MeV for the tensor glueball.Comment: 10 pages, 2 figures,typos correcte

    Jet conversions in a quark-gluon plasma

    Get PDF
    Quark and gluon jets traversing through a quark-gluon plasma not only lose their energies but also can undergo flavor conversions. The conversion rates via the elastic q(qˉ)g→gq(qˉ)q(\bar q)g\to gq(\bar q) and the inelastic qqˉ↔ggq\bar q\leftrightarrow gg scatterings are evaluated in the lowest order in QCD. Including both jet energy loss and conversions in the expanding quark-gluon plasma produced in relativistic heavy ion collisions, we have found a net conversion of quark to gluon jets. This reduces the difference between the nuclear modification factors for quark and gluon jets in central heavy ion collisions and thus enhances the p/π+p/\pi^+ and pˉ/π−{\bar p}/\pi^- ratios at high transverse momentum. However, a much larger net quark to gluon jet conversion rate than the one given by the lowest-order QCD is needed to account for the observed similar ratios in central Au+Au and p+p collisions at same energy. Implications of our results are discussed.Comment: version to appear in PR

    Ion mixing to produce amorphous Mo-Ru superconducting films

    Get PDF
    Amorphous Mo55Ru45 alloy films were formed by ion mixing of multilayered samples. The ion mixed films, which contain no metalloid element, show excellent superconducting properties. The measured properties are correlated with the microstructure obtained by both x-ray diffraction and transmission electron microscopy

    Quantum Statistical Entropy and Minimal Length of 5D Ricci-flat Black String with Generalized Uncertainty Principle

    Full text link
    In this paper, we study the quantum statistical entropy in a 5D Ricci-flat black string solution, which contains a 4D Schwarzschild-de Sitter black hole on the brane, by using the improved thin-layer method with the generalized uncertainty principle. The entropy is the linear sum of the areas of the event horizon and the cosmological horizon without any cut-off and any constraint on the bulk's configuration rather than the usual uncertainty principle. The system's density of state and free energy are convergent in the neighborhood of horizon. The small-mass approximation is determined by the asymptotic behavior of metric function near horizons. Meanwhile, we obtain the minimal length of the position Δx\Delta x which is restrained by the surface gravities and the thickness of layer near horizons.Comment: 11pages and this work is dedicated to the memory of Professor Hongya Li

    Comparison of Canonical and Grand Canonical Models for selected multifragmentation data

    Get PDF
    Calculations for a set of nuclear multifragmentation data are made using a Canonical and a Grand Canonical Model. The physics assumptions are identical but the Canonical Model has an exact number of particles, whereas, the Grand Canonical Model has a varying number of particles, hence, is less exact. Interesting differences are found.Comment: 12 pages, Revtex, and 3 postscript figure
    • …
    corecore