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

Experimental confirmation of the QCD critical point is an excellent test of QCD theory in the non-perturbative region and a milestone of exploring the QCD phase diagram. It is one of the main goals of the RHIC Beam Energy Scan (BES) program. Due to the high sensitivity to the correlation length [1] of the dynamical system and directly connected to the susceptibilities in theoretical...

Fluctuations of conserved charges measured in Heavy-Ion Collisions (HICs) received increasing attention in recent years, because they are good candidates to explore the phase diagram of QCD matter. During last year, net-electric charge and net-proton moments of multiplicities measured at RHIC have been published by the STAR collaboration, for a range of collision energies which spans a region...

Hydrodynamics is successfully applied as a theoretical model for the dynamics of heavy ion collisions at high collision energies reached at RHIC and the LHC. However, the applicability for collisions at lower beam energies remains unclear. Known limitations are both physical, such as possible lack of thermalization, large mean free path or large fluctuations, and technical, such as negative...

Scintillation detectors will be an important part of detection systems in FAIR. In order to extract maximum information from the scintillation pulses, improved signal processing is required. Due to the stochastic nature of the pulse creation in a scintillation detector the output pulses are not all of the same shape but rather 'noised' with statistical fluctuations on the pulse tails, which...

The region of large net-baryon densities in the QCD phase diagram is expected to exhibit a first-order phase transition. Experimentally, its study will be one of the primary objectives for the upcoming FAIR accelerator. We model the transition between quarks and hadrons in a heavy-ion collision using a fluid which is coupled to the explicit dynamics of the chiral order parameter. This allows...

The CBM experiment at FAIR is being designed to study heavy-ion collisions at extremely high interaction rates. The event selection has to be done online and requires full event topology reconstruction, therefore fast and efficient reconstruction algorithms are needed. The Cellular Automaton track finder is fast and robust and thereby will be used for the online and offline track...

The HADES spectrometer currently operating on the beam of SIS18 accelerator in GSI will be moved to a new position in the CBM/HADES cave of the future FAIR complex. Electromagnetic calorimeter (ECAL) will enable the HADES@FAIR experiment to measure data on neutral meson production in heavy ion collisions at the energy range of 2-10 A GeV on the beam of the new accelerator SIS100@FAIR....

The nuclear equation of state (EOS) at high density is still an unresolved issue though many theoretical and experimental efforts have been made in the last five decades. It is believed that compact stars such as neutron stars (NS) consist of hadronic and strange quark or color superconducting matter. Stars having a quark core surrounded by hadronic matter, may be considered as hybrid stars...

I will discuss challenges and open questions for the thoeretical description of systems created at the CBM experiment at FAIR. In particular I will focus on issues for hadronic bulk observables which can be adressed by transport models. Of particular interest is the possible phase transition of QCD expected to occur at the FAIR beam energy range. I will discuss what progress has been made...

The CBM experiment at FAIR will explore the QCD phase diagram in the region of high net baryonic densities and moderate temperatures by colliding heavy ions at beam energies up to 45 GeV/nucleon. The physics program includes the study of the equation-of-state of nuclear matter in mentioned region of the phase diagram and the search for the de-confinement and chiral phase transition, and the...

We discuss the prospects of computing thermal dilepton rates from first principles lattice QCD. The focus lies in the determination of the meson vector-vector current spectral function in the low mass region. We review and compare recent results from continuum-extrapolated, quenched calculations, as well as dynamical two-flavor setups. Additionally we update our two-flavor dynamical analysis...

We investigate the effects of (axial)vector mesons on the chiral phase transition in the framework of an SU(3), (axial)vector meson extended linear sigma model with additional constituent quarks and Polyakov loops. We determine the parameters of the Lagrangian at zero temperature in a hybrid approach, where we treat the mesons at tree-level, while the constituent quarks at 1-loop level. We...

Certain aspects of the behavior of strongly interacting matter can be understood in terms of effective models. Among such models is the quark meson model. With a suitable choice of parameters and field content the phase diagram exhibits a 1st order phase transition that terminates in a critical point at nonzero chemical potential. We apply a method developed by Carter and extended to the...

In Au+Au-collisions at 1.23 AGeV, the complete strangeness production is below its nucleon-nucleon threshold. In baryon dominated matter K+ and K− exhibit different properties, because K- can be resonantly absorbed by nucleons. Although strangeness exchange reactions have been proposed to be the dominant channel for K− production below threshold, the production yield could also be explained...

In heavy ion collisions at beam energies of 1-2 AGeV, strangeness production can be observed below its elementary production threshold. In April and May 2012, 7.3 billion Au(1.23 GeV per nucleon)+Au collisions have been recorded by the HADES detector, installed at the Helmholtzzentrum fuer Schwerionenforschung (GSI) in Darmstadt, Germany. In this collision system the weakly decaying strange...

The HADES (High Acceptance Di-Electron Spectrometer) at the GSI Helmholtzzentrum für Schwerionenforschung investigates dilepton and strangeness production in elementary and heavy-ion collisions. In April - May 2012 HADES recorded 7 billion Au+Au events at a beam energy of 1.23 GeV/u with the highest multiplicities measured so far. The track reconstruction and particle identification in...

The PANDA (anti-Proton ANnihiliation at DArmstadt) experiment will be a multi-purpose apparatus at the future Facility for Antiproton and Ion Research (FAIR) at Darmstadt. Anti-proton induced reactions with 1.5 to 15 GeV/c beam momentum at high luminosities of up to 2*10^32/(s*cm^2) will be investigated. Exclusive detection of whole events with almost 4pi acceptance and high precision are...

We calculate the spectrum of light mesons, charmonium and bottomonium, for total momenta J=0..3 in the Dyson-Schwinger/Bethe-Salpeter approach to QCD, using the rainbow-ladder approximation in combination with an effective interaction. We find two new states in the nnbar and ssbar channels for J=3--, with masses 1528(184) MeV and 1752(94) MeV respectively, that compare well with the...

Low energy resonances appear as final states of the processes that are produced in proton-proton collisions. Thus, in order to analyse the results that will be obtained by the PANDA experiment, it is necessary to control the low energy sector of hadron spectroscopy. The extended Linear Sigma Model (eLSM) describes scalar, pseudoscalar, vector and axial-vector meson resonances, the glueball,...

We present a U(4)r × U(4)l chiral symmetric model, which includes scalar and pseudoscalar mesons as well as vector and axial-vector mesons. We compute charmed mesons masses, weak decay constants, and strong decay widths of (open and hidden) charmed mesons. Moreover, we calculate the decay width of a pseudoscalar ground state charmonium ɳc into a pseudoscalar glueball and the decay widths of a...

In this talk, I will present the recent BESIII results on hadron spectroscopy. BESIII has accumulated a large data example of electron-positron annihilations at the energies ranging from 3GeV to 4.6GeV. BESIII is a general-purpose spectrometer and provide excellent performance in particle detection in the energy range of interest. This talk covers the most recent physics outputs at...

Low-mass dilepton pairs from heavy-ion collisions are considered good probes for chiral symmetry restoration and the in-medium properties of vector mesons. However, the complexity of the different contributing sources is a challenge for theory; a satisfying description of dilepton production in heavy-ion collisions covering all energy ranges from SIS to LHC is yet to be found. Transport...

We have investigated the survival probability of different charmonium states, in a high baryon density parton plasma, expected to be produced in nuclear collisions at FAIR. Charmonia are assumed undergo complete dissociation by color screening, if the in-medium Debye radius becomes comparable to the spatial size of the corresponding bound state. Results indicate a non-trivial dependence of the...

High energy proton microscopy (HEPM) is an emerging diagnostic technique which provides unique capabilities in penetrating radiography including the combination of high spatial resolution and accuracy of density reconstruction inside volumes and in situ environments. Since the proton beam is composed of charged particles, the beam may be focused with magnetic lenses to form images of the...

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One of the main goals of the PANDA experiment is the search of non-conventional quark-antiquark states, such as glueballs, hybrids and tetraquark and/or also molecular states. The energy region between 2.5-5 GeV is especially interesting because it is expected to locate many non-conventional mesons and will be carefully investigated by the PANDA experiment. In the talk I review the present...

When solids are exposed to energetic ions (MeV-GeV), their physical and chemical structure can severely be modified. The change is governed by ultrafast dynamical processes starting from the deposition of large energy densities, electronic excitation and ionization processes, and finally damage creation in the atomic lattice system. Each projectile creates a cylindrical track with a few...

The ultra-precise measurement of the g-factor of highly-charged ions provides a unique possibility to probe the validity of the Standard Model under extreme conditions. The bound electron is exposed to electric fields of up to 10^16 V/m, yielding a high sensitivity for higher-order contributions and hypothetical physics beyond the Standard Model. We have determined the g-factor of hydrogen-...

The TRIGA-SPEC facility at the TRIGA research reactor at the University of Mainz is dedicated to high-precision measurements of ground-state properties of neutron-rich radionuclides far from stability. TRIGA-SPEC consists of the Penning-trap mass spectrometer TRIGA-TRAP and the collinear laser spectroscopy setup TRIGA-LASER. The measurements provide access to nuclear binding energies,...

A topical review on the experimental physics for NUSTAR experiments at FAIR. State-of-the-art experimental devices for nuclear physics studies, such as the R3B setup and the AGATA/GRETINA gamma-ray energy-tracking arrays, will be presented and the kind of experiments possible with them will be discussed.

The field of nuclear physics is interested in the understanding of the properties of nuclei in and beyond the drip-line, especially the last decade the interest in research on halo and non-bound nuclei has been growing fast [1, 2]. This contribution is about a study of the unbound system 13Be produced from a 14B (p, 2p) reaction at high energy. The experiment was performed in complete...

This talk deals with the investigation of the characteristics of prompt gamma ray emission in radiotherapy with carbon ions. The aim of this investigation was to study the principle of using the prompt gamma rays, created by nuclear reactions of the incident therapy beam with the irradiated tissue, to determine the position of the Bragg peak during the medical treatment. Developing a system...

Studies of the polarization of hard x-rays emitted in energetic heavy-ion atom collisions provide detailed information of the collision dynamics as well as of the atomic structure at high-Z [1]. Moreover, hard x-ray polarimetry also opens a route for polarization diagnosis of spin-polarized ion and electron beams as are discussed for future PNC experiments at FAIR [2]. However, due to the lack...

We introduce transverse densities in the study of parton dynamics in the proton's peripheral region. We calculate these densities using Chiral perturbation theory (ChPT) and parametrize the long distance structure of the nucleon in a model independent framework in which we identify chiral (b~O(M_pi^(⁻1))) and molecular (b~O(M_N^2/(M_pi^(3)))) parametrical regions. Through the light cone...

Hybrid static potentials are computed using lattice gauge theory with particular focus on small quark-antiquark separations. The resulting potentials are used to estimate masses of hybrid mesons.

Fluctuations of conserved charges, such as electric charge, baryon number and strangeness, are proving to be a promising and useful tool to investigate the deconfinement phase transition of QCD and recently also the freeze-out dynamics in heavy-ion collisions (HICs). Lattice QCD calculations involving higher order susceptibilities have shown some first indications that a flavour...

The Forward Spectrometer developed for the PANDA detector will consist of many different detection systems allowing for a precise track reconstruction and particle identification. A feasibility studies done for the forward spectrometer will be presented. In the first part results of the simulations will be shown with the focus on studies of particle occupancies of the tracking stations. In...

Where do the atoms in your body come from? This question can be answered by invoking ideas from nuclear, particle, and astro physics. The field of nucleosynthesis combines these disciplines by studying processes in nature that create nuclei from pre-existing nucleons or from other nuclei. In this talk I discuss basic concepts of nuclear reactions and astrophysical environments. I provide an...

We investigate the structure of proton-rich isotope 8B in the Fermionic Molecular Dynamics (FMD) formalism. The structure of 8B is important for stellar nucleosynthetic reaction rates in the pp chain and for determining the high-energy solar neutrino flux. 8B is difficult to access experimentally, making microscopic calculations especially valuable for determination of associated reaction...

Antibaryon-nucleus bound states J. Hrtankova, J. Mares Nuclear Physics Institute, 250 68 Rez, Czech Republic The study of the antibaryon-nucleus interaction is an interesting issue as it provides valuable information about the behavior of the antibaryon ($\bar{B}$) in nuclear medium, the in-medium $\bar{B}N$ interaction as well as nuclear dynamics. The possibility of the existence of...

Lepton pairs emerging from decays of virtual photons represent promising probes of matter under extreme conditions. In the energy domain of 1 - 2 GeV per nucleon, the HADES experiment at GSI Helmholtzzentrum fuer Schwerionenforschung in Darmstadt studies di-electrons and strangeness production in various reactions, i.e. collisions of pions, protons, deuterons and heavy-ions with nuclei. An...

Heavy-ion collisions play a very important role in studying of relativistic quantum dynamics of electrons in the presence of strong electromagnetic fields [J. Eichler and W. E. Meyerhof, Relativistic Atomic Collisions, (Academic Press, New York, 1995)]. What is more, if the total charge of the colliding nuclei is larger than the critical one, Z1 + Z2 > 173, such collisions can provide a unique...

High-precision measurements of the g-factor of highly charged ions are among the physics topics of the FLAIR collaboration within the framework of FAIR. Simultaneous experimental and theoretical study of the g-factor of light hydrogen-like ions provided the best up-to-date determination of the electron mass [1]. First ppb-precision measurement for lithium-like system has been accomplished...

We report on an investigation of tetraquark candidates with two very heavy quarks. These two quarks are treated in the static limit, while the other two are dynamical u, d, s or c twisted mass quarks. Different isospin, spin and parity quantum numbers are considered. The relation to systems of four dynamical quarks is discussed.

We investigate the phase structure of QCD at finite temperature and light-quark chemical potential. We improve upon earlier results for Nf=2+1 dynamical quark flavors and investigate the effects of charm quarks in an extension to Nf=2+1+1. We determine the quark condensate and the Polyakov loop potential using solutions of a coupled set of (truncated) Dyson-Schwinger-equations for the quark...