Frankfurt Institute for Advanced Studies

About: Frankfurt Institute for Advanced Studies is a facility organization based out in Frankfurt am Main, Germany. It is known for research contribution in the topics: Baryon & Quark–gluon plasma. The organization has 798 authors who have published 2733 publications receiving 82799 citations. The organization is also known as: FIAS.

Beam energy dependence of the squeeze-out effect on the directed and elliptic flow in Au + Au collisions in the high baryon density region

Abstract: We present a detailed analysis of the beam energy dependence of the mechanisms for the generation of directed and elliptic flows in Au + Au collisions focusing on the role of hadronic rescattering and spectator shadowing within a microscopic transport model jam with different equations of state. A systematic study of the beam energy dependence is performed for Au + Au collisions at $\sqrt{{s}_{\mathit{NN}}}=2.3\ensuremath{-}62.4$ GeV. The transition of the dynamical origin of the directed flow is observed. We find that the initial Glauber-type nucleon-nucleon collisions generate negative ${v}_{1}$ for nucleons at midrapidity due to the presence of spectator matter, and this negative nucleon ${v}_{1}$ is turned to be positive by the meson-baryon interactions at the beam energy region of $\sqrt{{s}_{NN}}l30$ GeV. In contrast, above 30 GeV there is no spectator shadowing at midrapidity, and initial nucleon-nucleon collisions do not generate directed flow, but subsequent rescatterings among produced particles generate negative ${v}_{1}$ for nucleons. It is demonstrated that negative pion-directed flows are mostly generated by the interaction with the spectator matter. It is also shown that the squeeze-out effect is largely suppressed in the case of softening, which leads to the enhancement of elliptic flow around $\sqrt{{s}_{NN}}=5\ensuremath{-}7$ GeV. The elliptic flow at midrapidity above 10 GeV is not influenced by the squeeze-out due to spectator matter, while its effect is seen at the forward rapidity range of $y/{y}_{\mathrm{c}.\mathrm{m}.}g0.5$, which decreases as beam energy increases.

Technical design report for the PANDA Barrel DIRC detector

Abstract: This documents describes the technical design and the expected performance of the Barrel DIRC detector for the PANDA experiment. The Barrel DIRC will provide hadronic charged particle identification in the polar angle range of $22^\circ$ to $140^\circ$ for particle momenta between 0.5 GeV/c and 3.5 GeV/c. The design is based on the successful BaBar DIRC with several key improvements. The performance and system cost were optimized in detailed detector simulations and validated with full system prototypes using particle beams at GSI and CERN. The final design meets or exceeds the PID goal of clean $\pi/K$ separation with at least 3 standard deviations over the entire phase space of charged kaons in the Barrel DIRC.

Hydrodynamic modeling of the deconfinement phase transition in heavy-ion collisions in the NICA-FAIR energy domain

Abstract: We use (3 + 1) dimensional ideal hydrodynamics to describe the space-time evolution of strongly interacting matter created in Au + Au and Pb + Pb collisions. The model is applied for the domain of bombarding energies 1-160 GeV/nucleon which includes future NICA (Dubna) and FAIR (Darmstadt) experiments. Two equations of state are used, the first one corresponding to resonance hadron gas and the second one including the deconfinement phase transition. The initial state is represented by two Lorentz-boosted nuclei. Dynamic trajectories of matter in the central box of the system are analyzed. They can be well represented by a fast shock-wave compression followed by a relatively slow isentropic expansion. The parameters of collective flows and hadronic spectra are calculated under assumption of the isochronous freeze-out. It is shown that the deconfinement phase transition leads to broadening of proton rapidity distributions, increase of elliptic flows, and formation of the directed antiflow in the central rapidity region. These effects are most pronounced at bombarding energies around 10 GeV/nucleon, when the system spends the longest time in the mixed phase. From the comparison with three-fluid calculations we conclude that the transparency effects are not so important in central collisions at NICA-FAIR energiesmore » (below 30 GeV/nucleon).« less

Planar channelling of 855 MeV electrons in silicon: Monte Carlo simulations

Abstract: A new Monte Carlo code for the simulation of the channelling of ultrarelativistic charged projectiles in single crystals is presented. A detailed description of the underlying physical model and the computation algorithm is given. The first results obtained with the code for the channelling of 855 MeV electrons in silicon crystal are presented. The dechannelling lengths for (1 0 0), (1 1 0) and (1 1 1) crystallographic planes are estimated. In order to verify the code, the dependence of the intensity of the channelling radiation on the crystal dimension along the beam direction is calculated. A good agreement of the obtained results with recent experimental data is observed.

Design and implementation of multi-signal and time-varying neural reconstructions.

Abstract: Several efficient procedures exist to digitally trace neuronal structure from light microscopy, and mature community resources have emerged to store, share, and analyze these datasets. In contrast, the quantification of intracellular distributions and morphological dynamics is not yet standardized. Current widespread descriptions of neuron morphology are static and inadequate for subcellular characterizations. We introduce a new file format to represent multichannel information as well as an open-source Vaa3D plugin to acquire this type of data. Next we define a novel data structure to capture morphological dynamics, and demonstrate its application to different time-lapse experiments. Importantly, we designed both innovations as judicious extensions of the classic SWC format, thus ensuring full back-compatibility with popular visualization and modeling tools. We then deploy the combined multichannel/time-varying reconstruction system on developing neurons in live Drosophila larvae by digitally tracing fluorescently labeled cytoskeletal components along with overall dendritic morphology as they changed over time. This same design is also suitable for quantifying dendritic calcium dynamics and tracking arbor-wide movement of any subcellular substrate of interest.