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

In the Compressed Baryonic Matter (CBM) experiment at FAIR strongly interacting matter at highest baryonic densities will be produced, which offers unprecedented opportunities for the investigation of this yet unexplored region of the QCD phase diagram. It will fill the gap in understanding bulk properties like the equation of state between the quark-gluon plasma at vanishing baryonic density...

The Compressed Baryonic Matter (CBM) experiment at the future FAIR facility will investigate high baryon density matter at moderate temperatures in A+A collisions from 3-35 AGeV. One of the key observables of the CBM physics program is electromagnetic radiation from the early fireball carrying undistorted information on its conditions to the detector. This includes detailed investigations of...

Based on the 2PI quantum effective action of the linear sigma model with constituent quarks, we develop a transport approach to study systems out of equilibrium. In particular, we focus on the chiral phase transition as well as the critical point in QCD, where nonequilibrium effects near the phase transition give rise to critical behavior of the ordering parameter. Predictions for long-range...

The FAIR facility will make the region of high net-baryon densities experimentally accessible, where a first-order phase transition is conjectured. We investigate the dynamics of chiral symmetry breaking and the onset of confinement during a heavy-ion collision at large baryochemical potentials within a nonequilibrium chiral fluid dynamics model including effects of dissipation and noise. The...

I will report on recent perturbative studies of the hot and dense QCD equation of state, via two different resummed perturbation theories. Using Hard-Thermal-Loop perturbation theory (HTLpt), the full one-loop pressure as well as various diagonal quark number susceptibilities are derived. In addition, the same quantities are computed by resummation of the well known four-loop finite density...

Medium dependent spectral properties of qQ mesons are evaluated by means of QCD sum rules at non-zero nucleon densities and/or temperatures. The well-known operator product expansion (OPE) of qQ mesons in medium up to mass dimension 5 is extended to four-quark condensate contributions of mass dimension 6. A complete catalogue of four-quark condensates in the qQ sector is presented. The...

The PANDA experiment will be carried out at the future FAIR facility, it will be a fixed target experiment, where antiproton beams, of unprecedented quality and intensity, will be used to study interaction on protons and on nuclei. PANDA will be an excellent tool to investigate final states which include short-lived particles. Since different charmonium states can be accessed in direct...

The aim of the PANDA (AntiProton ANnihilation at DArmstadt) experiment at FAIR is to improve our knowledge of the strong interaction and of the structure of hadrons. In particular, the study of electromagnetic processes (pbarp->e+e-, pbarp-> e+e-π0, etc.. ) gives access to the proton structure (electric and magnetic time like form factors, Transition Distribution Amplitudes, Generalized...

Two parameters that have a strong influence on the finite temperature QCD transition, and play an important role in various physical scenarios are the quark density and the external magnetic field. The effect of these parameters on the thermal properties of QCD will be discussed, and an overview of the latest lattice results will be given.

I review outstanding issues in the sector of scalar mesons with particular emphasis on reasons why a scalar glueball has not yet been unambiguously identified and how PANDA possesses the potential to resolve this important question of low-energy QCD. Such an effort will require input from theory that will also be discussed.

The shell structure of heavy nuclei with Z > 104, which can be produced in the actinide-based complete fusion reactions, is studied with modied two-center shell model. Using microscopic-macroscopic approach, the mass excesses and Q_alpha - values are calculated and compared with available experimental data. The predicted properties of superheavy nuclei show that the next doubly magic nucleus...

We study the pair-production of heavy mesons in proton-antiproton annihilations within a perturbative QCD motivated framework [A.T. Goritschnig, B. Pire and W. Schweiger, Phys.Rev. D87 (2013) 014017]. In particular we investigate p \bar{p} to \bar{D^0} D^0 within a double handbag approach, where the hard process ud ubar dbar to cbar c factorizes from soft matrix elements of c q q operators....

Whereas the strong interaction is successfully described by perturbative QCD for processes with large scales, QCD in the confinement domain remains one of the most challenging problems in contemporary physics. Generally the scale of a specific process needs to be larger than the QCD cut-off (~200 MeV) in order to be treated perturbatively. The mass of the strange quark (~150 MeV), is very...

The High Acceptance Di-Electron Spectrometer experiment, installed at GSI, Darmstadt, has measured rare penetrating probes and strange particles production in elementary nucleon-nucleon as well as in heavy ion collisions. In recent years, an upgrade of the data acquisition system was carried out and a major improvement of the spectrometer in terms of granularity and particle identification...

Lepton pairs emerging from decays of virtual photons are considered to be the most promising probes of dense hadronic matter. The HADES experiment at GSI studies dielectron radiation as well as strangeness production in various proton, deuteron and heavy-ion induced reactions. The understanding of the corresponding experimental results calls for supporting studies from transport calculations....

The lepton pair production process in collisions of antiproton beam (E_beam = 15 GeV) with proton target in PANDA experiment is studied on the basis of event samples simulated with PYTHIA6 generator and PandaRoot package. The considered quark level subprocesses goes through the production of virtual photon which converts into the lepton pair (q qbar --> gamma* --> e+e-). Such...

We discuss recent results on the properties of strange and heavy flavored mesons in hot hadronic matter. The strange meson sector is studied within a chiral unitary approach in coupled channels for kaon/antikaon nucleon interactions. As an application, we focus on the in-medium cross sections in several channels (such as Kbar N -> pi Sigma), which are of particular interest for microscopic...

HADES is a versatile detector located at GSI Helmholtzzentrum für Schwerionenforschung and currently operating at the SIS18 accelerator in the range of beam kinetic energies of 1-2 GeV/u (for nucleus-nucleus collisions), up to 3.5 GeV in proton-induced reactions. The ultimate goal of the HADES experimental program is to reveal signals of hadron modification expected to occur at non-zero...

The Compressed Baryonic Matter (CBM) Experiment will explore the phase diagram of strongly interacting matter in the region of high net baryon densities. The experiment is laid out for nuclear collisions at rates up to 10 MHz, the highest in the field. A unique wide spectrum of observables will be accessible, including rarest probes like hadrons containing charm quarks, or multi-strange...

We calculate the transport coefficients for D mesons in a finite-temperature bath, populated by light mesons and baryons. Using the Fokker-Planck formalism, the drag force and diffusion coefficients are obtained as a function of temperature, baryonic chemical potential and particle content.  The interaction with light mesons and baryons is described with the help of effective field...

The exposure to high charge and energy (HZE) particles is one of major concerns for humans during their missions in space. As radiation effects essentially depend on charge, mass and energy of cosmic-ray particles, the radiation quality has to be investigated, e.g. by means of microdosimetry measurements on the board of a spacecraft. In microdosimetry a Tissue Equivalent Proportional Counter...

Experimental and theoretical investigations of nuclei far away from stability became a vital and active research field in nuclear physics in the past decades. With the advent of radioactive beam facilities, isotopes close to the driplines can be produced and their structure is studied via scattering experiments at intermediate and high energies. Neutron-proton asymmetric nuclei, i.e....

For the understanding of the strong nuclear force, the interaction of mesons with nuclei is important. In case of long lived charged mesons, like $\pi$ and $K$, secondary beams can be used for experiments. But the situation is different for the short lived neutral mesons, like $\eta$ and $\eta'$. The only access is indirect, making use of final-state interaction. The mesons are...

Semileptonic decays Ds-> e + ν + π,η,η’ are an excellent environment for precision measurements of the CKM matrix element |Vcd| and |Vcs|. These decays are governed by both the weak and strong forces; extraction of the weak CKM parameters requires knowledge of strong interaction effects. These can be parameterized by form factors, which encapsulate the QCD bound-state effects. Techniques such...

Elliptic flow has been one of the key observables for establishing the finding of the quark-gluon plasma (QGP) at the highest energies of Relativistic Heavy Ion Collider (RHIC) and the Large Hadron Collider (LHC). As a sign of collectively behaving matter, one would expect the elliptic flow to decrease at lower beam energies, where the QGP is not produced. However, in the recent RHIC beam...

Computations with weakly-coupled plasmas and some lattice results suggest that the heavy quarkonium potential has an imaginary part that is important in order to study dissociation. This imaginary part is due to the inelastic scattering with partons in the medium. At temperatures much below dissociation another process that is known to be important is the so-called gluo-dissociation. The aim...

The Compressed Baryonic Matter (CBM) experiment will be one of the major scientific pillars of the future Facility for Antiproton and Ion Research (FAIR) in Darmstadt. The goal of the CBM research program is to explore the QCD phase diagram in the region of high net baryon densities using high-energy nucleus-nucleus collisions. This includes the study of the equation-of-state of nuclear matter...

In the Compressed Baryonic Matter (CBM) experiment at FAIR, the Silicon Tracking System (STS) will perform track reconstruction and momentum determination of the charged particles created in interactions of heavy-ion beams with nuclear targets. The STS will consist out of 8 tracking layers located at distances between 30 cm and 100 cm downstream of the target inside the 1 T magnetic dipole...

Using the U(3)R x U(3)L extended Linear Sigma Model (eLSM) with ordinary mesonic degrees of freedom and glueballs we calculate decay widths in order to study their vacuum interactions at low energy and in particular the nature of the resonances f0(1370), f0(1500) and f0(1710). In this context the understanding of the mixing behaviour in the scalar-isoscalar sector is essential.

The physics program of the PANDA (anti-Proton ANhiliation ar DArmstadt) experiment will address various questions related to the strong interactions by employing a multi-purpose detector system at the High Enery Storage Ring for anti-protons of the upcoming Facility for Anti-proton and Ion Research (FAIR). The excellent antiproton beam resolution of Δp/p ≈ 10-5 and the high luminosity...

I review the status of an ongoing long-term lattice investigation of the spectrum and structure of tetraquark candidates. I will focus on light scalar mesons, e.g. a_0(980). First steps and future plans regarding heavier tetraquark candidates, in particular those containing charm quarks, will also be outlined.

We propose to describe the process $ p \bar{p} \rightarrow \pi^- pi^+ $ in a perturbative QCD motivated framework where a double-handbag hard process $ ud \bar{u} \bar{d} \rightarrow d \bar{d} $ factorizes from transition distribution amplitudes (TDAs). A TDA describes the non-perturbative transition of the proton to the meson by emission of 2 quarks and absorption of an antiquark ...

An effective field theory for the weak ΛN-->NN interaction has been developed up to next-to-next-to leading order. The relation between the low energy constants appearing in the leading order effective field theory description and the parameters of the one-meson-exchange model previously developed are obtained. We extract the relative importance of the different exchange...

We shall present the new lattice data on Polyakov loop susceptibilities in SU(3) pure gauge system. Like the Polyakov loops, the susceptibilities can serve as the order parameter for the spontaneous Z(3) center symmetry breaking. In the context of Polyakov loop effective models, these susceptibilities are related to the curvatures of the potential. We shall discuss how the new data can be...

We study scalar, pseudoscalar, vector, and axial-vector mesons as well as octet and decouplet baryons with non-strange and strange quantum numbers in the framework of a linear sigma model with global chiral U_L(3)xU_R(3) symmetry for the mesons and SU_L(3)xSU_R(3) for the baryons. We perform a global fit of meson masses, decay widths, as well as decay amplitudes. The quality of the fit is, for...

The PANDA-Experiment at the future FAIR facility in Darmstadt will implement a Micro-Vertex-Detector (MVD) and a large-volume Straw Tube Tracker (STT) around the target interaction region together with a set of GEM disks for the charged particle tracking within a 2 T solenoidal magnetic field. The STT is a gas based detector which is comprised of 4636 cylindrical drift chambers (straw tubes)...

The masses of hadrons like protons and neutrons are considered to be partially due to the result of the spontaneous chiral symmetry breaking. The chiral symmetry is known to be restored in hot or dense medium and the order parameter of the chiral symmetry breaking <qbar q > diminishes. We need to study this effect quantitatively in order to improve our understanding of the origin of...

Next generation of radioactive ion beam facilities like FAIR and detectors like AGATA will open a bright future for nuclear structure and nuclear astrophysics research. In particular, very exotic nuclei (mainly neutron rich) isotopes will be produced and a lot of new exciting experimental data will help to test and improve the current nuclear models. In addition, these data (masses, reaction...

Microscopic transport models are frequently used to investigate dilepton production in nuclear collisions, but usually they have difficulties to deal with in-medium effects in heavy-ion collisions. We present an alternative approach that uses coarse-grained output from transport calculations with the UrQMD model to determine thermal dilepton emission rates. For this purpose, a four-dimensional...

We employ the up-to-date version of viscous Hydro-Kinetic Model (vHKM) based on 3+1D viscous hydrodynamic code coupled to UrQMD hadron cascade. Following the experimental program at BNL RHIC, we perform a similar "energy scan" in the model, and study the collision energy dependence of charged and identified hadron spectra, flow coefficients and femtoscopic radii. For this aim the equation of...

The main purpose of the report is to present NICA/MPD Project, particularly the Multi-purpose detector's structure and physical goals and also the current stage of its performance. NICA is a new accelerator complex being constructed at JINR, Dubna, Russia. The global scientific goal of the NICA/MPD project is to explore the phase diagram of strongly interacting matter in the region of...