T. Gaitanos | Aristotle University of Thessaloniki (original) (raw)

Papers by T. Gaitanos

International Journal of Modern Physics E-nuclear Physics, 2008

Heavy Ion Collisions (HIC) represent a unique tool to probe the in-medium nuclear interaction in ... more Heavy Ion Collisions (HIC) represent a unique tool to probe the in-medium nuclear interaction in regions away from saturation. In this work we present a selection of reaction observables in dissipative collisions particularly sensitive to the isovector part of the interaction, i.e.to the symmetry term of the nuclear Equation of State (EoS). At low energies the behavior of the symmetry

Physical Review C, 2010

The nuclear breathing-mode giant monopole resonance is studied within an improved relativistic Bo... more The nuclear breathing-mode giant monopole resonance is studied within an improved relativistic Boltzmann-Uehling-Uhlenbeck (BUU) transport approach. As a new feature, the numerical treatment of ground state nuclei and their phase-space evolution is realized with the same semiclassical energy density functional. With this new method a very good stability of ground state nuclei in BUU simulations is achieved. This is important in extracting clear breathing-mode signals for the excitation energy and, in particular, for the lifetime from transport theoretical studies including mean-field and collisional effects.

Nuclear Physics A, 2004

We investigate in detail the density dependence of the symmetry energy in a relativistic descript... more We investigate in detail the density dependence of the symmetry energy in a relativistic description by decomposing the iso-vector mean field into contributions with different Lorentz covariant properties. We find important effects of the iso-vector, scalar channel (i.e. δ-meson like) on the high density behavior of the symmetry energy. Applications to static properties of finite nuclei and to dynamic situations of heavy ion collisions are explored and related to each other. The nuclear structure studies show only moderate effects originating from the virtual δ meson. At variance, in heavy ion collisions one finds important contributions on the reaction dynamics arising from the different Lorentz structure of the high density symmetry energy when a scalar iso-vector δ field is introduced. Particularly interesting is the related neutron/proton effective mass splitting for nucleon transport effects and for resonance and particle production around the threshold. We show that the δ-like channel turns out to be essential for the production of pions, when comparing with experimental data, in particular for high momentum selections.

Arxiv preprint nucl-th/ …, 2000

We discuss the problems involved in extracting the nuclear equation-of-state from heavy-ion colli... more We discuss the problems involved in extracting the nuclear equation-of-state from heavy-ion collisions. We demonstrate that the equation of state becomes effectively softer in non-equilibrium and this effect is observable in terms of collective flow effects. Thus, non-equilibrium effects must be included in transport descriptions on the level of the effective mean fields. A comparison with transverse momentum, rapidity, and centrality selected flow data show the reliability and limitations of the underlying interaction which was derived from microscopic Dirac-Brueckner (DB) results.

Journal of Physics G: Nuclear and Particle Physics, 2005

We compare multiplicities as well as rapidity and transverse momentum distributions of protons, p... more We compare multiplicities as well as rapidity and transverse momentum distributions of protons, pions and kaons calculated within presently available transport approaches for heavy ion collisions around 1 AGeV. For this purpose, three reactions have been selected: Au+Au at 1 and 1.48 AGeV and Ni+Ni at 1.93 AGeV.

Hyperfine Interactions, 2012

The results of the microscopic transport calculations ofp-nucleus interactions within a GiBUU mod... more The results of the microscopic transport calculations ofp-nucleus interactions within a GiBUU model are presented. The dominating mechanism of hyperon production is the strangeness exchange processesKN → Yπ andKN → ΞK. The calculated rapidity spectra of Ξ hyperons are significantly shifted to forward rapidities with respect to the spectra of S = −1 hyperons. We argue that this shift should be a sensitive test for the possible exotic mechanisms ofp-nucleus annihilation. The production of the double Λ-hypernuclei by Ξ − interaction with a secondary target is calculated.

$Research paper thumbnail of Formation of double-$\ Lambda $ hypernuclei at PANDA$

We study the formation of single-and double-Λ hypernuclei in antiproton-induced reactions relevan... more We study the formation of single-and double-Λ hypernuclei in antiproton-induced reactions relevant for the forthcoming PANDA experiment at FAIR. We use the Giessen Boltzmann-Uehling-Uhlenbeck (GiBUU) transport model with relativistic mean-fields for the description of non-equilibrium dynamics and the statistical multifragmentation model (SMM) for fragment formation. This combined approach describes the dynamical properties of strangeness and fragments in low energypinduced reactions fairly well. We then focus on the formation of double-Λ hypernuclei in high energyp-nucleus collisions on a primary target including the complementary Ξ-induced reactions to a secondary one, as proposed by the PANDA Collaboration. Our results show that a copious production of double-Λ hyperfragments is possible at PANDA. In particular, we provide first theoretical estimations on the double-Λ production cross section, which strongly rises with decreasing energy of the secondary Ξ-beam.

... Since pre-dictions critically depend on the underlying equations of state (EoS) they have to ... more ... Since pre-dictions critically depend on the underlying equations of state (EoS) they have to be carefully verifi ed by compari-son to available data. ... A constraint on the stiffness of the EoS has been derived by analysing elliptic fl ow data from heavy ion collisions (HIC) at SIS and ...

Progress in Particle and Nuclear Physics, 2004

We present several possibilities offered by the reaction dynamics of dissipative heavy ion collis... more We present several possibilities offered by the reaction dynamics of dissipative heavy ion collisions to study in detail the symmetry term of the nuclear equation of state, EOS. In the Fermi energy domain we discuss isospin effects on the nuclear liquid-gas phase transition, Isospin Distillation, and on mid-rapidity fragment formation in semicentral collisions. The correlation between isospin diffusion and deviations from the Viola systematics will be analysed. Collective flows are studied at intermediate energies in order to extract observables sensitive to the nucleon effective mass splitting at high isospin density.