25,429 research outputs found
On finite volume effects in the chiral extrapolation of baryon masses
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 (NLO), 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- 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 NLO are
predicted. In particular we extract a pion-nucleon sigma term of 39
MeV and a strangeness sigma term of the nucleon of MeV. The flavour SU(3) chiral limit of the baryon octet and
decuplet masses is determined with MeV and 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
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
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
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
Short arc orbital constraints for adjustment of geodetic satellite dat
SECOR observations in the Pacific
Geometric adjustment technique for Pacific SECOR observations based on least squares metho
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