Engineering topics

Konchakovski, V P

Publications and source records attributed to Konchakovski, V P.

3 records

DOE OSTI2012

Dynamics of hot and dense nuclear and partonic matter

The dynamics of hot and dense nuclear matter is discussed from the microscopic transport point of view. The basic concepts of the Hadron-String-Dynamical transport model (HSD)-derived from Kadanoff-Baym equations in phase phase-are presented as well as 'highlights' of HSD results for different observables in heavy-ion collisions from 100 A MeV (SIS) to 21 A TeV(RHIC) energies. Furthermore, a novel extension of the HSD model for the description of the partonic phase-the Parton-Hadron-String-Dynamics (PHSD) approach-is introduced. PHSD includes a nontrivial partonic equation of state-in line with lattice QCD-as well as covariant transition rates from partonic to hadronic degrees of freedom. The sensitivity of hadronic observables to the partonic phase is demonstrated for relativistic heavy-ion collisions from the FAIR/NICA up to the RHIC energy regime.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

DOE OSTI2011

Electromagnetic field evolution in relativistic heavy-ion collisions

The hadron string dynamics (HSD) model is generalized to include the creation and evolution of retarded electromagnetic fields as well as the influence of the magnetic and electric fields on the quasiparticle propagation. The time-space structure of the fields is analyzed in detail for noncentral Au + Au collisions at {radical}(s{sub NN})=200 GeV. It is shown that the created magnetic field is highly inhomogeneous, but in the central region of the overlapping nuclei it changes relatively weakly in the transverse direction. For the impact parameter b=10 fm, the maximal magnetic field - perpendicularly to the reaction plane - is obtained of order eB{sub y}/m{sub {pi}}{sup 2}{approx}5 for a very short time {approx}0.2 fm/c, which roughly corresponds to the time of a maximal overlap of the colliding nuclei. We find that at any time, the location of the maximum in the eB{sub y} distribution correlates with that of the energy density of the created particles. In contrast, the electric field distribution, being also highly inhomogeneous, has a minimum in the center of the overlap region. Furthermore, the field characteristics are presented as a function of the collision energy and the centrality of the collisions. To explore the effect of the back reaction of the fields on hadronic observables, a comparison of HSD results with and without fields is exemplified. Our actual calculations show no noticeable influence of the electromagnetic fields--created in heavy-ion collisions--on the effect of the electric charge separation with respect to the reaction plane.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗

DOE OSTI2010

Jets propagation through a hadron-string medium

Di-jet correlations in nucleus-nucleus collisions are studied within the hadron-string-dynamics (HSD) transport approach taking into account the reaction of the medium on the jet energy loss nonperturbatively. A comparison with the STAR and PHENIX data in central Au+Au collisions at the Relativistic Heavy Ion Collider energy {radical}(s)=200 GeV is performed differentially (i.e., with respect to correlations in azimuthal angle {Delta}{phi} and pseudorapidity {Delta}{eta}). The HSD results do not show enough suppression for the 'away-side' jets in accordance with earlier perturbative studies. Furthermore, the 'Mach-cone' structure for the angle distribution in the away-side jet as well as 'ridge' long-range rapidity correlations in the 'near-side' jet - observed by the STAR, PHENIX, and PHOBOS Collaborations - are not seen in the HSD results, thus suggesting a partonic origin.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗