相关论文: Core-corona separation in the UrQMD hybrid model
The Ultrarelativistic Quantum Molecular Dynamics [UrQMD] model is widely used to simulate heavy ion collisions in broad energy ranges. It consists of various components to implement the different physical processes underlying the transport…
These proceedings present recent results from transport-hydrodynamics-hybrid models for heavy ion collisions at relativistic energies. The main focus is on the absorption of (anti-)protons in the hadronic afterburner stage of the reaction,…
The UrQMD model with a density dependent equation of state, including a first-order phase transition, is used to study the time dependence of baryon number and proton number susceptibilities up to third order in heavy ion reactions of…
The centrality determination and the estimated fluctuations of number of participant nucleons $N_{part}$ in Au-Au collisions at 1.23 $A$GeV beam kinetic energy suffers from severe model dependencies. Comparing the Glauber Monte Carlo (MC)…
Significant advances in numerical techniques have enabled recent breakthroughs in the study of various properties of the Hubbard model - a seemingly simple, yet complex model of correlated electrons that has been a focus of study for more…
The hadronic phase in ultrarelativistic nuclear collisions has a large influence on final state observables like multiplicity, flow and $p_t$ spectra, as studied in the UrQMD approach. In this model one assumes that a non-equilibrium…
Local kinetic and chemical equilibration is studied for Au+Au collisions at 10.7 AGeV in the microscopic Ultrarelativistic Quantum Molecular Dynamics model (UrQMD). The UrQMD model exhibits dramatic deviations from equilibrium during the…
The acceleration of charged particles is relevant to the solar corona over a broad range of scales and energies. High-energy particles are usually detected in concomitance with large energy release events like solar eruptions and flares,…
Measurements of energy separations in highly charged ions can in many cases nowadays be performed with very high accuracy, an accuracy that sometimes cannot be matched by the corresponding theoretical calcula- tions. Furthermore, it has…
The centrality dependence of spectra of identified particles in collisions between ultrarelativistic heavy ions with a center of mass energy ($\sqrt{s}$) of 39 and 11.5 $AGeV$ is analyzed in the core - corona model. We show that at these…
The time evolution of particle number fluctuations in nuclear collisions at intermediate energies ($E_{\rm lab} = 1.23-10A$ GeV) is studied by means of the UrQMD-3.5 transport model. The transport description incorporates baryonic…
It is extremely difficult to simulate the details of coronal heating and also make meaningful predictions of the emitted radiation. Thus, testing realistic models with observations is a major challenge. Observational signatures of coronal…
We discuss the status of thermal model descriptions of particle ratios in central nucleus-nucleus collisions at ultra-relativistic energy. An alternative to the ``Cleymans-Redlich'' interpretation of the freeze-out trajectory is given in…
The density profile of a hot nuclear system produced in intermediate energy heavy ion collisions is studied in a microcanonical formulation with a momentum and density dependent finite range interaction. The caloric curve and the density…
Mix-cumulants of conserved charge distributions are sensitive observables for probing properties of the QCD medium and phase transition in heavy-ion collisions. To perform precise measurements, efficiency correction is one of the most…
Condensations in the more than 10^6 K hot corona of the Sun are commonly observed in the extreme ultraviolet (EUV). While their contribution to the total solar EUV radiation is still a matter of debate, these condensations certainly provide…
Coronal active regions are observed to get fuzzier and fuzzier (i.e. more and more confused and uniform) in harder and harder energy bands or lines. We explain this evidence as due to the fine multi-temperature structure of coronal loops.…
We propose and explore a new hybrid approach to jet quenching in a strongly coupled medium. The basis of this phenomenological approach is to treat physics processes at different energy scales differently. The high-$Q^2$ processes…
We investigate the hydrodynamics of the QCD plasma using dimensionless numbers built from the thermodynamics and transport theory of the plasma and characteristic dimensions of the fireball produced in heavy-ion collisions. We find that by…
Direct photon emission in heavy-ion collisions is calculated within the relativistic microscopic transport model UrQMD. We compare the results from the pure transport calculation to a hybrid-model calculation, where the high-density part of…