66,622 research outputs found
Tomographic Studies of the sQGP
Azimuthal correlation functions are used to study jet- and di-jet properties
as a function of centrality in Au+Au collisions at =200
GeV. Utilizing a novel technique to decompose the correlation function into a
(di-)jet and an underlying event, the jet-pair distribution is extracted and
compared to similar results for d+Au collisions obtained at the same collision
energy. A striking similarity is observed between the widths and associated
yields of the (di-)jet distributions for d+Au and peripheral Au+Au collisions.
By contrast, the distributions for mid-central Au+Au collisions indicate an
increase in the di-jet yield with centrality, and a very broad away-side jet
having a possible minimum at . These features point to
significant medium induced modification to the away-side jet and are compatible
with recent predictions of jet-induced "conical flow".Comment: Proc. 21st. Winter Workshop on Nuclear Dynamic
A duality for the double fibration transform
We establish a duality within the spectral sequence that governs the
holomorphic double fibration transform. It has immediate application to the
questions of injectivity and range characterization for this transform. We
discuss some key examples and an improved duality that holds in the Hermitian
holomorphic case
MHOs toward HMOs: A Search for Molecular Hydrogen emission-line Objects toward High-Mass Outflows
We present the results of a narrow-band near-infrared imaging survey for
Molecular Hydrogen emission-line Objects (MHOs) toward 26 regions containing
high-mass protostellar candidates and massive molecular outflows. We have
detected a total of 236 MHOs, 156 of which are new detections, in 22 out of the
26 regions. We use H 2.12-m/H 2.25-m flux ratios, together
with morphology, to separate the signatures of fluorescence associated with
photo-dissociation regions (PDRs) from shocks associated with outflows in order
to identify the MHOs. PDRs have typical low flux ratios of ~ 1.5 - 3, while the
vast majority of MHOs display flux ratios typical of C-type shocks (~ 6-20). A
few MHOs exhibit flux ratios consistent with expected values for J-type shocks
(~ 3-4), but these are located in regions that may be contaminated with
fluorescent emission. Some previously reported MHOs have low flux ratios, and
are likely parts of PDRs rather than shocks indicative of outflows. We identify
a total of 36 outflows across the 22 target regions where MHOs were detected.
In over half these regions, MHO arrangements and fluorescent structures trace
features present in CO outflow maps, suggesting the CO emission traces a
combination of dynamical effects, which may include gas entrained in expanding
PDRs as well as bipolar outflows. Where possible, we link MHO complexes to
distinct outflows and identify candidate driving sources.Comment: 40 pages, 40 figures, accepted for publication in the Astrophysical
Journa
Analysis of Dilepton Invariant Mass Spectrum in C+C at 2 and 1 AGeV
Recently the HADES collaboration has published the invariant mass spectrum of
pairs, dN/dM, produced in C+C collisions at 2 AGeV. Using
electromagnetic probes, one hopes to get in this experiment information on
hadron properties at high density and temperature. Simulations show that firm
conclusions on possible in-medium modifications of meson properties will only
be possible when the elementary meson production cross sections, especially in
the pn channel, as well as production cross sections of baryonic resonances are
better known. Presently one can conclude that a) simulations overpredict by far
the cross section at if free production
cross sections are used and that b) the upper limit of the decay into
is smaller than the present upper limit of the Particle Data Group.
This is the result of simulations using the Isospin Quantum Molecular Dynamics
(IQMD) approach.Comment: 28 pages, 15 figures, 3 tables, ps file recommende
Measuring the Decorrelation Times of Fourier Modes in Simulations
We describe a method to study the rate at which modes decorrelate in
numerical simulations. We study the XY model updated with the Metropolis and
Wolff dynamics respectively and compute the rate at which each eigenvector of
the dynamics decorrelates. Our method allows us to identify the decorrelation
time for each mode separately. We find that the autocorrelation function of the
various modes is markedly different for the `local' Metropolis compared to the
`non-local' Wolff dynamics. Equipped with this new insight, it may be possible
to devise highly efficient algorithms.Comment: 16 pp (LaTeX), PUPT-1378 , IASSNS-HEP-93/
Comparing Hemp Seed Yields (Cannabis sativa L.) of an On-Farm Scientific Field Experiment to an On-Farm Agronomic Evaluation Under Organic Growing Conditions in Lower Austria
Hemp seed yields of the variety Fedora-19 in an on-farm scientific field experiment on small plots and in an on-farm evaluation in 11 hemp fields under practical organic growing conditions in Lower Austria were compared to give a realistic view of the variability of yields. Dry matter seed yields from the on-farm field experiment ranged from 127 to 143 g/m2. Under practical growing conditions, yields ranged from 34 to 151 g/m2 in the sample plots. The reported hemp seed yield after combine harvesting, drying, and cleaning was between 324 kg/ha and 717 kg/ha. The results of the experiment show that harvesting by hand considerably influences yields. Yields of the manual harvest in sample plots indicate a high correlation with yields harvested by the combine harvester (R2 = 0.91). The commercial yield is 71% of the yields recorded in sample plots in the fields. Our data questions the transfer of results and conclusions drawn from the data of scientific field experiments that employ manual harvest to that of practical circumstances, and support the notion of on-farm research
Zero temperature properties of mesons in a vector meson extended linear sigma model
A three flavor linear sigma model with vector and axial-vector mesons is
discussed. Preliminary results concerning on the symmetry breaking pattern, the
question of parameterization, as well as the resulting meson masses are
presented.Comment: 4 pages, 0 figures, submitted to the Hot and Cold Baryonic Matter
(HCBM 2010) conference proceeding
- …
