25,429 research outputs found

    On finite volume effects in the chiral extrapolation of baryon masses

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    We perform an analysis of the QCD lattice data on the baryon octet and decuplet masses based on the relativistic chiral Lagrangian. The baryon self energies are computed in a finite volume at next-to-next-to-next-to leading order (N3^3LO), where the dependence on the physical meson and baryon masses is kept. The number of free parameters is reduced significantly down to 12 by relying on large-NcN_c sum rules. Altogether we describe accurately more than 220 data points from six different lattice groups, BMW, PACS-CS, HSC, LHPC, QCDSF-UKQCD and NPLQCD. Values for all counter terms relevant at N3^3LO are predicted. In particular we extract a pion-nucleon sigma term of 39−1+2_{-1}^{+2} MeV and a strangeness sigma term of the nucleon of σsN=84−  4+28\sigma_{sN} = 84^{+ 28}_{-\;4} MeV. The flavour SU(3) chiral limit of the baryon octet and decuplet masses is determined with (802±4)(802 \pm 4) MeV and (1103±6)(1103 \pm 6) MeV. Detailed predictions for the baryon masses as currently evaluated by the ETM lattice QCD group are made.Comment: 44 pages, 10 figures and 6 tables - the revised manuscript contains the results of additional fits at the N^2LO level - 4 additional figures show the size of finite volume corrections for each lattice point - more technical details on the evaluation of finite volume effects are give

    Genus Topology of the Cosmic Microwave Background from the WMAP 3-Year Data

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    We have independently measured the genus topology of the temperature fluctuations in the cosmic microwave background seen in the Wilkinson Microwave Anisotropy Probe (WMAP) 3-year data. A genus analysis of the WMAP data indicates consistency with Gaussian random-phase initial conditions, as predicted by standard inflation. We set 95% confidence limits on non-linearities of -101 < f_{nl} < 107. We also find that the observed low l (l <= 8) modes show a slight anti-correlation with the Galactic foreground, but not exceeding 95% confidence, and that the topology defined by these modes is consistent with that of a Gaussian random-phase distribution (within 95% confidence).Comment: MNRAS LaTeX style (mn2e.cls), EPS and JPEG figure

    Abelian Duality

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    We show that on three-dimensional Riemannian manifolds without boundaries and with trivial first real de Rham cohomology group (and in no other dimensions) scalar field theory and Maxwell theory are equivalent: the ratio of the partition functions is given by the Ray-Singer torsion of the manifold. On the level of interaction with external currents, the equivalence persists provided there is a fixed relation between the charges and the currents.Comment: 11 pages, LaTeX, no figures, a reference added, submitted to Phys. Rev.

    Antarctic meteorite descriptions, 1980

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    Specimens found in the Alan Hills area include 361 ordinary chondrites, 4 carbonaceous chondrites, 6 achondrites, and 2 irons. Thirteen specimens measured over 11 cm in diameter and 69 between 5 to 10 cm in diameter are reported. The remainder of the finds were small, and many were paired. One of the irons was estimated to weigh about 20 kilograms

    The use of short arc orbital constraints in the adjustment of geodetic satellite data

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    Short arc orbital constraints for adjustment of geodetic satellite dat

    SECOR observations in the Pacific

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    Geometric adjustment technique for Pacific SECOR observations based on least squares metho
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