Refine
Year of publication
- 2013 (115) (remove)
Document Type
- Article (43)
- Doctoral Thesis (21)
- Conference Proceeding (15)
- Master's Thesis (15)
- Bachelor Thesis (10)
- Contribution to a Periodical (4)
- Book (3)
- Part of Periodical (3)
- Preprint (1)
Has Fulltext
- yes (115)
Is part of the Bibliography
- no (115)
Keywords
- LHC (2)
- Synchrotron (2)
- (F)EBID (1)
- ALICE LHC (1)
- ALICE experiment (1)
- Aktivierungsmethode (1)
- Akustik (1)
- Balance function (1)
- Beauty production (1)
- Boltzmann equation (1)
- CBM (1)
- Charge correlations (1)
- Charged-particle density (1)
- Chiral perturbation theory (1)
- Chiral symmetry (1)
- Correlations (1)
- Dense nuclear matter (1)
- Double-sided silicon microstrip detectors characterization readout quality assurance (1)
- Dynamical chiral symmetry breaking (1)
- Dyson–Schwinger equations (1)
- EuB6 (1)
- Fermion–gauge-boson vertex (1)
- Finite-Differenzen (1)
- Fluktuationsspektroskopie (1)
- Funktionale Renormierungsgruppe (1)
- Gabor lens (1)
- Gammaspektroskopie (1)
- HBT (1)
- Hallsensor (1)
- Heavy flavor (1)
- Heavy flavor production (1)
- Heavy-ion collisions (1)
- Heavy-ions (1)
- Historie (1)
- Hydrodynamic (1)
- In-medium pion mass (1)
- Integrator (1)
- Ionenbeschleuniger (1)
- Isospin (1)
- Keldysh-Formalismus (1)
- Kinetic Theory (1)
- Langsame Extraktion (1)
- Laute (1)
- Mach cones (1)
- Magnetfeld (1)
- Magnetfeldregelung (1)
- Magnetic field (1)
- Monte Carlo simulation (1)
- Nicht-linearer Transport (1)
- Optisches Potenzial (1)
- PENELOPE (1)
- Pickupspule (1)
- QCD (1)
- Quantum electrodynamics (1)
- Quark deconfinement (1)
- Quark–gluon plasma (1)
- Regelungssystem (1)
- Schottky (1)
- Shock Waves (1)
- Single electrons (1)
- Spinwellen (1)
- Synaptic plasticity (1)
- Tumortherapie (1)
- UrQMD (1)
- Wide rapidity coverage (1)
- Yttrium-Eisengranat (1)
- astrophysikalischer p-Prozess (1)
- axions (1)
- circadian rhythm (1)
- dark matter experiments (1)
- detector (1)
- diagnostics (1)
- electron backscattering (1)
- electron beam induced deposition (1)
- electron transport (1)
- genetic algorithm (1)
- heavy ions (1)
- ionizing radiation (1)
- liver, pancreas (1)
- nanotechnology (1)
- nnp (1)
- non-neutral plasma (1)
- nonneutral plasma (1)
- nukleare Wirkungsquerschnitte (1)
- optische Potentiale (1)
- organotypic slice culture (1)
- p-Kerne (1)
- pp collisions (1)
- resonant (1)
- solar physics (1)
- storage ring (1)
- tungsten (1)
- white and brown dwarfs (1)
Institute
- Physik (115) (remove)
ω(782) und ϕ(1020) Mesonenproduktion durch Dielektronen in pp-Kollisionen bei √s = 7 TeV mit ALICE
(2013)
Die Niedrigmassendielektronen (Elektron-Positron Paare mit kleiner invarianten Masse) sind wichtige experimentelle Sonden, um die Eigenschaften des in ultra-relativistischen Schwerionenkollisionen erzeugten heißen und dichten Mediums zu untersuchen. Elektronen koppeln nicht an die starke Wechselwirkung, weshalb sie wichtige Informationen über die gesamten Kollisionsphasen geben. Die Zerfälle von ω(782) und ϕ(1020)-Mesonen in Dielektronen ermöglichen es, besonders wichtige Informationen über ihre In-Medium-Eigenschaften zu erhalten, da Proton-Proton (pp)-Kollisionen als mediumfreie Referenz angenommen werden. Außerdem sind pp-Kollisionen auch für sich genommen interessant, um die Teilchenproduktion im Energiebereich des LHC (Large Hadron Collider) zu untersuchen.
In dieser Analyse werden die Elektronen im mittleren Rapiditätsbereich von |η| < 0.8 mit ITS (Inner Tracking System), TPC (Time Projection Chamber) und TOF (Time of Flight) gemessen.
Die transversalen Impulsspektren der ω(782) und ϕ(1020)-Mesonen im e+e--Zerfallskanal in pp-Kollisionen bei p √s = 7 TeV werden gezeigt. Das transversale Impulsspektrum des ω(782)-Mesons im e+e--Zerfallskanal wird mit den pT-Spektren in den µ+µ--und in den π0π+π--Zerfallskanälen verglichen, während das pT-Spektrum vom ϕ(1020)-Meson im e+e--Zerfallskanal mit den pT-Spektren in µ+µ-- und K+K--Zerfallskanälen verglichen wird.
The way we perceive the visual world depends crucially on the state of the observer. In the present study we show that what we are holding in working memory (WM) can bias the way we perceive ambiguous structure from motion stimuli. Holding in memory the percept of an unambiguously rotating sphere influenced the perceived direction of motion of an ambiguously rotating sphere presented shortly thereafter. In particular, we found a systematic difference between congruent dominance periods where the perceived direction of the ambiguous stimulus corresponded to the direction of the unambiguous one and incongruent dominance periods. Congruent dominance periods were more frequent when participants memorized the speed of the unambiguous sphere for delayed discrimination than when they performed an immediate judgment on a change in its speed. The analysis of dominance time-course showed that a sustained tendency to perceive the same direction of motion as the prior stimulus emerged only in the WM condition, whereas in the attention condition perceptual dominance dropped to chance levels at the end of the trial. The results are explained in terms of a direct involvement of early visual areas in the active representation of visual motion in WM.
In high-energy nuclear collisions, heavy quark potential at finite temperature controls the quarkonium suppression. Including the relaxation of the medium induced by the relative velocity between quarkonia and the deconfined expanding matter, the Debye screening is reduced and the quarkonium dissociation takes place at a higher temperature. As a consequence of the velocity-dependent dissociation temperature, the quarkonium suppression at high transverse momentum is significantly weakened in high-energy nuclear collisions at RHIC and LHC.
Die Dissertation betrachtet zunächst die Anatomie der Lautentstehung und die Historie von Untersuchungen zu Sprechtraktakustik (u.a. Ibn Sina, Hook, Mical, Kratzenstein, Kempelen, Faber, Wheatstone, Helmholz, Riesz, Dunn, Chiba, Kajiyama, Kelly, Lochbaum, Saito, Itakura, Burg ) und geht insbesondere auf das Rohrmodell zu Beschreibung der Vokaltraktakustik ein.
Mittels Finiter-Differenzen wird die Aksutik der Sprechens dann dreidimensional beschrieben, und die zuätzlich auftretenden Effekte betrachtet. Fur die sich beim Sprechen schnell bewegende Mundhöhle wird ein Verfahren entwickelt und untersucht, mittels Sprachsignalen durch inverse Filterung und MRT-Aufnahmen die räumliche Konfiguration zu bestimmen. Für den Nasaltrakt wurden dreidimensional abbildende Verfahren aus der medizinischen Diagnostik verglichen (MRT und CT), und anhand eines Computer-Tomographischen Datensatzes die akustischen Vorgänge dreidimensional bestimmt.
The transverse momentum (pT) distribution of primary charged particles is measured in minimum bias (non-single-diffractive) p-Pb collisions at sNN−−−√=5.02 TeV with the ALICE detector at the LHC. The pT spectra measured near central rapidity in the range 0.5<pT<20 GeV/c exhibit a weak pseudorapidity dependence. The nuclear modification factor RpPb is consistent with unity for pT above 2 GeV/c. This measurement indicates that the strong suppression of hadron production at high pT observed in Pb-Pb collisions at the LHC is not due to an initial-state effect. The measurement is compared to theoretical calculations.
Using a partonic transport model we investigate the evolution of conical structures in ultrarelativistic matter. Using two different source terms and varying the transport properties of the matter we study the formation of Mach Cones. Furthermore, in an additional study we extract the two-particle correlations from the numerical calculations and compare them to an analytical approximation. The influence of the viscosity to the shape of Mach Cones and the corresponding two-particle correlations is studied by adjusting the cross section of the medium.
We investigate the phase structure of strongly interacting matter at non-vanishing isospin before the onset of pion condensation in the framework of the unquenched Polyakov–Quark-Meson model with 2+1 quark flavors. We show results for the order parameters and all relevant thermodynamic quantities. In particular, we obtain a moderate change of the pressure with isospin at vanishing baryon chemical potential, whereas the chiral condensate decreases more appreciably. We compare the effective model to recent lattice data for the decrease of the pseudo-critical temperature with the isospin chemical potential. We also demonstrate the major role played by the value of the pion mass in the curvature of the transition line, and the need for lattice results with a physical pion mass. Limitations of the model at nonzero chemical potential are also discussed.
The width of the ω meson in cold nuclear matter is computed in a hadronic many-body approach, focusing on a detailed treatment of the medium modifications of intermediate πρ states. The π and ρ propagators are dressed by their self-energies in nuclear matter taken from previously constrained many-body calculations. The pion self-energy includes Nh and Δh excitations with short-range correlations, while the ρ self-energy incorporates the same dressing of its 2π cloud with a full 3-momentum dependence and vertex corrections, as well as direct resonance-hole excitations; both contributions were quantitatively fit to total photo-absorption spectra and πN→ρN scattering. Our calculations account for in-medium decays of type ωN→πN(⁎),ππN(Δ), and 2-body absorptions ωNN→NN(⁎),πNN. This causes deviations of the in-medium ω width from a linear behavior in density, with important contributions from spacelike ρ propagators. The ω width from the ρπ cloud may reach up to 200 MeV at normal nuclear matter density, with a moderate 3-momentum dependence. This largely resolves the discrepancy of linear T–ϱ approximations with the values deduced from nuclear photoproduction measurements.
The Compressed Baryonic Matter (CBM) experiment [1] is a fixed target heavy-ion experiment that will operate at the international Facility for Antiproton and Ion Research (FAIR) [2] now under construction in Darmstadt, Germany. The experiment intends to study rare probes, which are emitted from heavy ion collisions with a beam energy of 4 to 45 AGeV. A focus is laid to the short lived open charm particles and to particles decaying into di-lepton pairs. Handling the up to 107 Au+Au collisions/s required for generating those probes with sufficient statistics, as much as reaching the required sensitivity for observing them, forms a major challenge for the silicon detectors of the experiment. We present the concept and the development status of two central detectors of CBM, the CMOS pixel based micro vertex detector (MVD) and the micro-strip detector based silicon tracking system (STS).
22nd International Workshop on Vertex Detectors, 15-20 September 2013 Lake Starnberg, Germany