4,598 research outputs found
Elliptic flow of resonances at RHIC: probing final state interactions and the structure of resonances
We propose the measurement of the elliptic flow of hadron resonances at the
Relativistic Heavy Ion Collider as a tool to probe the amount of hadronic final
state interactions for resonances at intermediate and large transverse momenta.
This can be achieved by looking at systematic deviations of the measured flow
coefficient from the scaling law given by the quark recombination
formalism. Our method can be generalized to explore the structure of exotic
particles, such as the recently found pentaquark .Comment: 5 pages, 2 figures; v2: accepted version for publication in Physical
Review C rapid communication
Hadronization in heavy ion collisions: Recombination and fragmentation of partons
We argue that the emission of hadrons with transverse momentum up to about 5
GeV/c in central relativistic heavy ion collisions is dominated by
recombination, rather than fragmentation of partons. This mechanism provides a
natural explanation for the observed constant baryon-to-meson ratio of about
one and the apparent lack of a nuclear suppression of the baryon yield in this
momentum range. Fragmentation becomes dominant at higher transverse momentum,
but the transition point is delayed by the energy loss of fast partons in dense
matter.Comment: 4 pages, 2 figures; v2: reference [8] added; v3: Eq.(2) corrected,
two references added, version to appear in PR
MAESTRO, CASTRO, and SEDONA -- Petascale Codes for Astrophysical Applications
Performing high-resolution, high-fidelity, three-dimensional simulations of
Type Ia supernovae (SNe Ia) requires not only algorithms that accurately
represent the correct physics, but also codes that effectively harness the
resources of the most powerful supercomputers. We are developing a suite of
codes that provide the capability to perform end-to-end simulations of SNe Ia,
from the early convective phase leading up to ignition to the explosion phase
in which deflagration/detonation waves explode the star to the computation of
the light curves resulting from the explosion. In this paper we discuss these
codes with an emphasis on the techniques needed to scale them to petascale
architectures. We also demonstrate our ability to map data from a low Mach
number formulation to a compressible solver.Comment: submitted to the Proceedings of the SciDAC 2010 meetin
Resonance Production in RHIC Collisions
Results of resonance particle production measured at RHIC in 200 GeV Au+Au collisions are compared to measurements in p+p and d+Au
collisions in order to verify the existence of an extended hardronically
interacting medium. Yield and momentum distributions of resonances maybe
modified during the fireball lifetime due to resonance decay and the subsequent
rescattering of their decay daughters as well as the regeneration of resonances
from their decay products. Modified momentum spectra in heavy ion collisions
may change the nuclear modification factor R. The influence on the
elliptic flow v due to late regeneration of resonances is discussed.Comment: 6 pages, 6 figures, Proceedings of the 22st Winter Workshop on
Nuclear Dynamics, San Diago, California, 12-18 March, 200
Charge diffusion constant in hot and dense hadronic matter - A Hadro-molecular-dynamic calculation
We evaluate charge diffusion constant of dense and hot hadronic matter based
on the molecular dynamical method by using a hadronic collision generator which
describes nuclear collisions at energies 10 < E < 100 GeV/A and satisfies
detailed balance at low temperatures (T < 200 MeV). For the hot and dense
hadronic matter of the temperature range, 100 < T < 200 MeV and baryon number
density, 0.16 < nB < 0.32 fm^-3, charge diffusion constant D gradually
increases from 0.5 fm c to 2 fm c with temperature and is almost independent of
baryon number density. Based on the obtained diffusion constant we make simple
discussions on the diffusion of charge fluctuation in ultrarelativistic nuclear
collisions.Comment: 13 pages, 4 figure
Progression of myopathology in Kearns-Sayre syndrome
We report on the progression of myopathology by comparing two biopsies from a patient with a Kearns-Sayre-Syndrome. The first biopsy was taken in 1979 and showed 10% ragged-red fibers. Myopathic changes were slight including internal nuclei and fiber splitting in 10% of the fibers. Electron microscopy revealed typical mitochondrial abnormalities with regard to number and shape. In 1989 a second biopsy was performed for an extended analysis of mitochondrial DNA. This time less than 5% of all fibers were ragged-red. Severe myopathic changes could be detected which so far has rarely been reported in mitochondrial cytopathy
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