12 research outputs found
Describing transverse dynamics and space-time evolution at RHIC in a hydrodynamic model with statistical hadronization
A hydrodynamic model coupled to the statistical hadronization code
Therminator is used to study a set of observables in the soft sector at RHIC. A
satisfactory description of the pT-spectra and elliptic flow is obtained,
similarly to other hydrodynamic models. With the Gaussian initial conditions
the transverse femtoscopic radii are also reproduced, providing a possible
solution of the RHIC HBT puzzle.Comment: to appear in the conference proceedings for Quark Matter 2009, March
30 - April 4, Knoxville, Tennesse
Functionalized Superparamagnetic Iron Oxide Nanoparticles (SPIONs) as Platform for the Targeted Multimodal Tumor Therapy
Standard cancer treatments involve surgery, radiotherapy, chemotherapy, and immunotherapy. In clinical practice, the respective drugs are applied orally or intravenously leading to their systemic circulation in the whole organism. For chemotherapeutics or immune modulatory agents, severe side effects such as immune depression or autoimmunity can occur. At the same time the intratumoral drug doses are often too low for effective cancer therapy. Since monotherapies frequently cannot cure cancer, due to their synergistic effects multimodal therapy concepts are applied to enhance treatment efficacy. The targeted delivery of drugs to the tumor by employment of functionalized nanoparticles might be a promising solution to overcome these challenges. For multimodal therapy concepts and individualized patient care nanoparticle platforms can be functionalized with compounds from various therapeutic classes (e.g. radiosensitizers, phototoxic drugs, chemotherapeutics, immune modulators). Superparamagnetic iron oxide nanoparticles (SPIONs) as drug transporters can add further functionalities, such as guidance or heating by external magnetic fields (Magnetic Drug Targeting or Magnetic Hyperthermia), and imaging-controlled therapy (Magnetic Resonance Imaging)
Functionalized Superparamagnetic Iron Oxide Nanoparticles (SPIONs) as Platform for the Targeted Multimodal Tumor Therapy
Standard cancer treatments involve surgery, radiotherapy, chemotherapy, and immunotherapy. In clinical practice, the respective drugs are applied orally or intravenously leading to their systemic circulation in the whole organism. For chemotherapeutics or immune modulatory agents, severe side effects such as immune depression or autoimmunity can occur. At the same time the intratumoral drug doses are often too low for effective cancer therapy. Since monotherapies frequently cannot cure cancer, due to their synergistic effects multimodal therapy concepts are applied to enhance treatment efficacy. The targeted delivery of drugs to the tumor by employment of functionalized nanoparticles might be a promising solution to overcome these challenges. For multimodal therapy concepts and individualized patient care nanoparticle platforms can be functionalized with compounds from various therapeutic classes (e.g. radiosensitizers, phototoxic drugs, chemotherapeutics, immune modulators). Superparamagnetic iron oxide nanoparticles (SPIONs) as drug transporters can add further functionalities, such as guidance or heating by external magnetic fields (Magnetic Drug Targeting or Magnetic Hyperthermia), and imaging-controlled therapy (Magnetic Resonance Imaging)
Effects of a phase transition on HBT correlations in an integrated Boltzmann+Hydrodynamics approach
A systematic study of HBT radii of pions, produced in heavy ion collisions in
the intermediate energy regime (SPS), from an integrated (3+1)d
Boltzmann+hydrodynamics approach is presented. The calculations in this hybrid
approach, incorporating an hydrodynamic stage into the Ultra-relativistic
Quantum Molecular Dynamics transport model, allow for a comparison of different
equations of state retaining the same initial conditions and final freeze-out.
The results are also compared to the pure cascade transport model calculations
in the context of the available data. Furthermore, the effect of different
treatments of the hydrodynamic freeze-out procedure on the HBT radii are
investigated. It is found that the HBT radii are essentially insensitive to the
details of the freeze-out prescription as long as the final hadronic
interactions in the cascade are taken into account. The HBT radii and
and the ratio are sensitive to the EoS that is employed during
the hydrodynamic evolution. We conclude that the increased lifetime in case of
a phase transition to a QGP (via a Bag Model equation of state) is not
supported by the available data.Comment: 7 pages, 5 figures. Accepted by Phys. Lett.
The research project "Success Conditions for Individual Support With ICT in School" (Gelindi)
Der Beitrag stellt die Relevanz und Zielsetzung sowie das Forschungsdesign des BMBF-Forschungsprojekts „Gelingensbedingungen für die individuelle Förderung mit digitalen Medien in der Schule“ (Gelindi) vor. Zudem werden Transferperspektiven skizziert. (DIPF/Orig.)The article presents the relevance and objectives as well as the research design of the BMBF research project “Success Conditions for Individual Support With ICT in School” (Gelindi). In addition, transfer perspectives are outlined. (DIPF/Orig.
Status and promise of particle interferometry in heavy-ion collisions
After five years of running at RHIC, and on the eve of the LHC heavy-ion program, we highlight the status of femtoscopic measurements. We emphasize the role interferometry plays in addressing fundamental questions about the state of matter created in such collisions, and present an enumerated list of measurements, analyses and calculations that are needed to advance the field in the coming years
Space-time evolution and HBT analysis of relativistic heavy ion collisions in a chiral SU(3) x SU(3) model
The space-time dynamics and pion-HBT radii in central heavy ion-collisions at
CERN-SPS and BNL-RHIC are investigated within a hydrodynamic simulation. The
dependence of the dynamics and the HBT-parameters on the EoS is studied with
different parametrisations of a chiral SU(3) sigma-omega model. The
selfconsistent collective expansion includes the effects of effective hadron
masses, generated by the nonstrange and strange scalar condensates. Different
chiral EoS show different types of phase transitions and even a crossover. The
influence of the order of the phase transition and of the difference in the
latent heat on the space-time dynamics and pion-HBT radii is studied. A small
latent heat, i.e. a weak first-order chiral phase transition, or even a smooth
crossover leads to distinctly different HBT predictions than a strong first
order phase transition. A quantitative description of the data, both at SPS
energies as well as at RHIC energies, appears difficult to achieve within the
ideal hydrodynamical approach using the SU(3) chiral EoS. A strong first-order
quasi-adiabatic chiral phase transition seems to be disfavored by the pion-HBT
data from CERN-SPS and BNL-RHIC
Hadron production in central nucleus-nucleus collisions at chemical freeze-out
We analyze the experimental hadron yield ratios for central nucleus-nucleus
collisions in terms of thermal model calculations over a broad energy range,
=2.7-200 GeV. The fits of the experimental data with the model
calculations provide the thermal parameters, temperature and baryo-chemical
potential at chemical freeze-out. We compare our results with the values
obtained in other studies and also investigate more technical aspects such as a
potential bias in the fits when fitting particle ratios or yields. Using
parametrizations of the temperature and baryonic chemical potential as a
function of energy, we compare the model calculations with data for a large
variety of hadron yield ratios. We provide quantitative predictions for
experiments at LHC energy, as well as for the low RHIC energy of 62.4 GeV. The
relation of the determined parameters with the QCD phase boundary is discussed.Comment: 38 pages, 25 figures - accepted to Nucl. Phys. A; v2: update fits of
4pi data,update on NA44 data at top SPS, fits at top RHIC without resonances;
v3: include fits of absolute yields (appendix). Model calculations and data
files available at http://www-linux.gsi.de/~andronic/physics/s/s.htm
Experimental and Theoretical Challenges in the Search for the Quark Gluon Plasma: The STAR Collaboration's Critical Assessment of the Evidence from RHIC Collisions
We review the most important experimental results from the first three years
of nucleus-nucleus collision studies at RHIC, with emphasis on results from the
STAR experiment, and we assess their interpretation and comparison to theory.
The theory-experiment comparison suggests that central Au+Au collisions at RHIC
produce dense, rapidly thermalizing matter characterized by: (1) initial energy
densities above the critical values predicted by lattice QCD for establishment
of a Quark-Gluon Plasma (QGP); (2) nearly ideal fluid flow, marked by
constituent interactions of very short mean free path, established most
probably at a stage preceding hadron formation; and (3) opacity to jets. Many
of the observations are consistent with models incorporating QGP formation in
the early collision stages, and have not found ready explanation in a hadronic
framework. However, the measurements themselves do not yet establish
unequivocal evidence for a transition to this new form of matter. The
theoretical treatment of the collision evolution, despite impressive successes,
invokes a suite of distinct models, degrees of freedom and assumptions of as
yet unknown quantitative consequence. We pose a set of important open
questions, and suggest additional measurements, at least some of which should
be addressed in order to establish a compelling basis to conclude definitively
that thermalized, deconfined quark-gluon matter has been produced at RHIC.Comment: 101 pages, 37 figures; revised version to Nucl. Phys.
Relativistic Nucleus-Nucleus Collisions and the QCD Matter Phase Diagram
This review will be concerned with our knowledge of extended matter under the
governance of strong interaction, in short: QCD matter. Strictly speaking, the
hadrons are representing the first layer of extended QCD architecture. In fact
we encounter the characteristic phenomena of confinement as distances grow to
the scale of 1 fm (i.e. hadron size): loss of the chiral symmetry property of
the elementary QCD Lagrangian via non-perturbative generation of "massive"
quark and gluon condensates, that replace the bare QCD vacuum. However, given
such first experiences of transition from short range perturbative QCD
phenomena (jet physics etc.), toward extended, non perturbative QCD hadron
structure, we shall proceed here to systems with dimensions far exceeding the
force range: matter in the interior of heavy nuclei, or in neutron stars, and
primordial matter in the cosmological era from electro-weak decoupling (10^-12
s) to hadron formation (0.5 10^-5 s). This primordial matter, prior to
hadronization, should be deconfined in its QCD sector, forming a plasma (i.e.
color conducting) state of quarks and gluons: the Quark Gluon Plasma (QGP).Comment: 146 pages, 83 figure