Workshop for young scientists with research interests focused on physics at FAIR

In this talk I will review recent advances in the computation of transport coefficients of strongly-interacting theories using field-theory methods. In particular, I will make special emphasis on the computation of the shear and bulk viscosities, and aspects such as possible bounds in these coefficients, relationship with anomalies, sum rules, etcetera. The behavior of transport coefficients...

Introduction to the main ideas and highlights from recent measurements of the anisotropic flow and azimuthal correlations in a heavy-ion collisions by RHIC and LHC experiments will be presented.

We examine the quark percolation transition at finite density, discovered in [1] and generalized to the full phase diagram in [2]. We show that this transition has many of the characteristics claimed for quarkyonic matter as defined in [3]. The percolation transition should arise, in our physical world (3 colors, 2-3 flavors) at densities parametrically larger than normal nuclear density but...

The Equation of state (EoS) of hot and dense matter plays a fundamental role in the understanding of core-collapse supernova. A phase transition from hadronic to exotic phases might occur in the early post-bounce phase of a core collapse supernova. We investigate the emergence of strange hyperons in the dynamical collapse of a non-rotating massive star to a black hole. We follow the dynamical...

A central activity of the upcoming FAIR@GSI facility will be the use of antiprotons for a large variety of investigations at PANDA detector and AIC storage ring. The focus of the studies is on the one hand to understand antimatter-matter interactions and on the other hand to use antiproton beams for spectroscopic studies of hadrons. The aim of our work is to understand antinucleon-nucleon...

The BIOMAT facility at FAIR will allow measurements of the physical and biological effects for heavy ion beams with energies up to 10A GeV [1]. The evaluation of space radiation effects through the irradiation with particles and energies similar to those found at cosmic rays is possible. Such experiments are becoming ever more important with the increase of the duration of space missions. The...

RHIC results at top collisional energy ($\sqrt{s_{NN}}$ = 200 GeV) suggest a strongly coupled partonic matter, namely the Quark Gluon Plasma (QGP), has been formed in central Au+Au collisions. With the RHIC Beam Energy Scan a wide range in the QCD phase diagram temperature vs. baryon chemical potential is covered. A phase transition between the QGP and the hadron gas phase is expected in this...

The search for the critical point is one of the central issues that will be investigated in the upcoming FAIR project. For a profound theoretical understanding of the expected signals we go beyond thermodynamic studies and present a fully dynamical model for the chiral and deconfinement phase transition in heavy ion collisions. The corresponding order parameters are propagated by Langevin...

We present simulations of neutron-rich matter at subnuclear densities, like supernova matter, with the time-dependent Hartree-Fock approximation at temperatures of several MeV. This matter evolves into spherical rod-like and slab-like shapes and mixtures thereof. The simulations employ a full Skyrme interaction in a periodic three-dimensional grid. With an improved Minkowski analysis, all...

This talk will address the impact of astrophysical effects on terrestrial neutrino detectors. More specifically, the strong gravitational field around a black hole changes the neutrino fluxes emitted from the surrounding disk. We present effects of general relativity on the nucleosynthesis resulting from the interaction of the neutrinos emitted and matter outflowing such disks.

In this talk I will discuss both finite and infinite systems. The physical settings will range from heavy nuclei, to neutron stars, and down to ultracold atomic gases. More specifically, I intend to talk about quantum many-body theory in various forms, most notably energy-density functionals and microscopic Monte Carlo simulations on modern supercomputers. Touching upon many theoretical...

One of the fundamental objectives of experiments with ultra-relativistic heavy ions is the study of hadronic matter at high density and high temperature. Presumably matter at such high densities or temperatures shows effects like the restoration of chiral symmetry or the formation of a quark gluon plasma. In this presentation the information which can be obtained by analyzing baryonic and...

Photons, as all electromagnetic probes, can give direct access to the hot and dense phase of a heavy-ion reaction. We show calculations of direct photon emission at SiS100- and SiS-300 energies with the UrQMD-hybrid model. UrQMD is a full microscopic+macroscopic transport/fluiddynamics hybrid model with hadron- and string-driven equilibration phase, a full (3+1)-dimensional fluiddynamic...

I discuss recent progress for hadron properties that are obtained from solving Dyson-Schwinger, Bethe-Salpeter and Faddeev equations. The topics that will be addressed include: results for the nucleon's electromagnetic and axial form factors, for the nucleon-delta electromagnetic and pseudoscalar transition form factors, and a tetraquark interpretation of the lowest-lying scalar meson. A...

One of the main physics goals of HADES is to investigate spectral modifications of light vector mesons in strongly interacting matter via their dilepton (e+e−) decay channel. Theoretical models predict such modifications due to strong meson-baryon resonance coupling which can be also probed in elementary collisions. In 2007 electron-positron pair production has been measured in p+p reactions...

Electromagnetic form factors (EMFFs) are key ingredients to the understanding of the internal structure of composite particles like baryons, since they contain information about the spatial distributions of charge and current inside the particle. Thus, they are a physical and measurable manifestation of the nature of the baryon constituents and the dynamics that binds them...

Quantum Chromodynamics (QCD) has been accepted as the theory that describes the strong interactions, i.e., the interactions between quarks and gluons. QCD is an asymptotically free theory, hence, perturbation theory can be applied in the high energy regime, where many successful quantitative predictions have been made. The description of low energy QCD phenomena i.e, in the...

Strong magnetic fields, as produced during heavy ion collisions, are expected to influence the QCD phase structure. Therefore, theoretical investigations have been performed within effective model calculations as well as within lattice gauge theory and functional renormalization group frameworks. The findings opened up intense discussions since they were rather different and even...

We study a chiral Lagrangian which describes the two-body and three-body decays of a pseudoscalar glueball into scalar and pseudoscalar mesons. The branching ratios represent a clear and parameter free prediction of our approach. In agreement with Lattice simulations, we evaluate the decays for a pseudoscalar glueball with a mass of 2.6 GeV, which is in the reach of the future Panda experiment...

There is a range of QCD phenomena beyond the reach of first-principles QCD. The well-known running of the strong coupling induces a strongly bound, non-perturbative regime of QCD in which hadrons are formed. The non-perturbativity forces us to reach for effective approaches in order to understand hadron structures and interactions. These structures and interactions are particularly important...

The Compressed Baryonic Matter Experiment (CBM) will explore the phase diagram of hadronic matter in the regime of highest baryon densities. Nuclear fireballs created in heavy ion collisions of 8-45 AGeV beam energy will be studied with numerous probes, among them open charm and light vector mesons. Reconstructing those rare probes requires a vacuum compatible micro vertex detector (MVD) with...

We investigate the phase structure of QCD at finite temperature and chemical potential by solving a coupled set of truncated Dyson-Schwinger equations for the quark and gluon propagator. We take into account the full back-reaction of the quarks onto the Yang-Mills sector and we include the effects of strange quarks. We discuss the resulting thermal mass of the unquenched gluon propagator and...

The decay of the D-Meson as well as the J/Psi are key measurements of the future CBM experiment at FAIR. To contribute to these measurements the Transition Radiation Detector of the CBM experiment will provide electron-pion separation and will contribute to the experiment-wide tracking in an environment of unprecedented high particle fluxes. This talk will give an overview on the status of...

The hot and dense nuclear matter created in nuclear collisions at relativistic energies consists of a plasma of deconfined quarks and gluons. Due to their large mass, the charm quarks are mainly formed in the first instants of the nuclear collision and will consequently experience the full history of the system. It was predicted that the strongly bound $J/\psi$ state will be suppressed in...

The Compressed Baryonic Matter (CBM) experiment at the Facility for Antiproton and Ion Research (FAIR) at Darmstadt will be a dedicated heavy-ion experiment for the investigation of baryonic matter at highest net-baryon densities. The measurement of some of the key observables of the physics program of CBM requires clean and efficient electron identification which will be performed...

Photons and lepton pairs emerging from decays of virtual photons are the most promising probes of dense hadronic matter. In the energy domain of 1 - 2 GeV per nucleon, HADES has measured electron pairs in C+C, Ar+KCl, p+p, d+p and p+Nb collisions. For the first time the electron pairs were reconstructed from quasi-free n+p sub-reactions by detecting the proton spectator from the deuteron...

The study of event‐by‐event fluctuations of chemical (particle type) composition in high‐energy nucleus-nucleus collisions is a helpful tool to pin-down the properties of strongly interacting matter. Indeed, according to theoretical calculations, the QCD critical point may be signalled by a characteristic pattern in the measured fluctuations. In this contribution a new method for...

PANDA is a fixed target experiment that will be carried out at the future FAIR facility. PANDA will provide an excellent tool to address fundamental questions in the field of the hadronic physics, with a physics program that extends from the investigation of QCD to the test of fundamental symmetries. The Micro-Vertex-Detector (MVD) located in the innermost part of the central tracking system...

Hypernuclear research will be one of the main topics addressed by the PANDA experiment at the planned Facility for Antiproton and Ion Research FAIR at Darmstadt (Germany). Thanks to the use of stored antiproton beams, copious production of double Lambda hypernuclei is expected at the PANDA experiment, which will enable high precision gamma spectroscopy of such nuclei for the first...

The lepton pair production in PANDA experiment in collisions of antiproton beam (E_beam = 14 GeV) with proton target is studied on the basis of event samples simulated with PYTHIA6 generator. The considered quark level subprocesses goes through the production of virtual photon which converts into lepton pair (q qbar --> gamma* --> mu+mu-) having a continuous energy spectrum of the final...

We implemented a Langevin approach for heavy quarks to the UrQMD hybrid model, which provides a realistic background medium for the evolution in heavy ion collisions at FAIR energies. Here we used two different sets of drag and diffusion coefficients, a T-Matrix approach and a resonance model. In case of the resonance model we also implemented different decoupling temperatures of the...

Dilepton production in the SIS energy regime is analysed with the Ultra-relativistic Quantum Molecular Dynamics model. Invariant mass and transverse momentum spectra of electron-positron pairs in elementary and nucleus-nucleus collisions calculated with our transport approach are compared to the different experimental results published by the HADES collaboration. The model results give a good...

The HADES experiment, installed at the Helmholtzzentrum für Schwerionenforschung (GSI) accelerator facility in Darmstadt, investigates dielectron emission and strangeness production in various collision systems (p+p, p+n, p+A and A+A) in the 1-3.5 AGeV regime. The observed low-mass dielectron and cascade enhancement in intermediate heavy-ion collisions indicates the onset of medium effects,...

We investigate dilepton production at SIS energies with the GiBUU transport code [1] in a resonance model approach. In a first step, we fix the model parameters via dilepton spectra from elementary NN collisions (as measured by the DLS and HADES collaborations). We argue that a large part of the so-called 'DLS puzzle' is due to an improper understanding of the elementary reactions, and that...