1,043 research outputs found
Term and Quark Spin Content of the Nucleon
We report results of our calculation on the term and quark spin
content of the nucleon on the quenched lattice at . The disconnected insertions which involve contributions from the sea
quarks are calculated with the stochastic noise algorithm. As a physical
test of the algorithm, we show that the forward matrix elements of the vector
and pseudoscalar currents for the disconnected insertions are indeed consistent
with the known results of zero. We tried the Wuppertal smeared source and found
it to be more noisy than the point source. With unrenormalized
MeV, we find the term to be MeV. The
strange quark condensate in the nucleon is large, i.e. . For the quark spin content, we find
, , and . The flavor-singlet axial charge .Comment: contribution to Lattice '94; 3 page uuencoded ps fil
Search for sterile neutrinos in holographic dark energy cosmology: Reconciling Planck observation with the local measurement of the Hubble constant
We search for sterile neutrinos in the holographic dark energy cosmology by
using the latest observational data. To perform the analysis, we employ the
current cosmological observations, including the cosmic microwave background
temperature power spectrum data from the Planck mission, the baryon acoustic
oscillation measurements, the type Ia supernova data, the redshift space
distortion measurements, the shear data of weak lensing observation, the Planck
lensing measurement, and the latest direct measurement of as well. We
show that, compared to the CDM cosmology, the holographic dark energy
cosmology with sterile neutrinos can relieve the tension between the Planck
observation and the direct measurement of much better. Once we include
the measurement in the global fit, we find that the hint of the existence
of sterile neutrinos in the holographic dark energy cosmology can be given.
Under the constraint of the all-data combination, we obtain and , indicating
that the detection of in the holographic dark energy
cosmology is at the level and the massless or very light sterile
neutrino is favored by the current observations.Comment: 10 pages, 4 figures; typos corrected, published in PR
Stochastic Estimation with Noise
We introduce a noise for the stochastic estimation of matrix inversion
and discuss its superiority over other noises including the Gaussian noise.
This algorithm is applied to the calculation of quark loops in lattice quantum
chromodynamics that involves diagonal and off-diagonal traces of the inverse
matrix. We will point out its usefulness in its applications to estimating
determinants, eigenvalues, and eigenvectors, as well as its limitations based
on the structure of the inverse matrix.Comment: 6 pages, 1 postscript figure, UK/93-0
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