Refine
Year of publication
Document Type
- Preprint (564)
- Article (320)
- Part of a Book (1)
- Conference Proceeding (1)
Has Fulltext
- yes (886)
Is part of the Bibliography
- no (886)
Keywords
- Heavy Ion Experiments (18)
- Hadron-Hadron scattering (experiments) (11)
- Heavy-ion collision (6)
- LHC (5)
- Hadron-Hadron Scattering (4)
- Quark-Gluon Plasma (4)
- ALICE experiment (3)
- Heavy Ions (3)
- Jets and Jet Substructure (3)
- Beauty production (2)
- Charm physics (2)
- Experimental nuclear physics (2)
- Experimental particle physics (2)
- Jets (2)
- Lepton-Nucleon Scattering (experiments) (2)
- Particle and resonance production (2)
- Particle correlations and fluctuations (2)
- Pb–Pb collisions (2)
- Single electrons (2)
- pp collisions (2)
- ALICE (1)
- ALICE detector (1)
- Accelerators & Beams (1)
- Accelerators & storage rings (1)
- Anti-nuclei (1)
- Atomic & molecular beams (1)
- Atomic and Molecular Physics (1)
- Atomic, Molecular & Optical (1)
- Beam loss (1)
- Benjamin, Walter (1)
- Benutzeroberfläche (1)
- Büchner, Georg (1)
- Centrality Class (1)
- Centrality Selection (1)
- Charge-transfer collisions (1)
- Circular accelerators (1)
- Collective Flow (1)
- Computerlinguistik (1)
- Electron-pion identification (1)
- Electronic transitions (1)
- Electroweak interaction (1)
- Elliptic flow (1)
- Fibre/foam sandwich radiator (1)
- Hadron-Hadron Scattering Heavy (1)
- Hadron-hadron interactions (1)
- Head and neck Cancer (1)
- Heavy Ion Experiment (1)
- Heavy Quark Production (1)
- Heavy flavor production (1)
- Heavy ions (1)
- Heavy-flavour decay muons (1)
- Heavy-flavour production (1)
- Ideologie (1)
- Invariant Mass Distribution (1)
- Ionisation energy loss (1)
- Low & intermediate-energy accelerators (1)
- Lymphadenopathy (1)
- Mid-rapidity (1)
- Minimum Bias (1)
- Monte Carlo (1)
- Multi-strange baryons (1)
- Multi-wire proportional drift chamber (1)
- Neural network (1)
- Particle Correlations and Fluctuations (1)
- Photon counting (1)
- Phänomen (1)
- Production Cross Section (1)
- Properties of Hadrons (1)
- Proton–proton (1)
- QCD (1)
- Quark Gluon Plasma (1)
- Quark Production (1)
- Quark gluon plasma (1)
- Rapidity Range (1)
- Relativistic heavy ion physics (1)
- Relativistic heavy-ion collisions (1)
- Resolution Parameter (1)
- Rilke, Rainer Maria (1)
- Salivary gland diseases (1)
- Sonette an Orpheus (1)
- Stern <Motiv> (1)
- Stimme <Motiv> (1)
- Stimmenhören (1)
- Structured reporting (1)
- Suchmaschine (1)
- Systematic Uncertainty (1)
- TR (1)
- Time Projection Chamber (1)
- Tracking (1)
- Transition radiation detector (1)
- Trigger (1)
- Ultrasonography (1)
- Vector Boson Production (1)
- Wahn <Motiv> (1)
- Weltraum <Motiv> (1)
- Woyzeck (1)
- Xenon-based gas mixture (1)
- amino acid PET (1)
- artificial intelligence (1)
- dE/dx (1)
- glioma (1)
- heavy ion experiments (1)
- quark gluon plasma (1)
- spectra (1)
- treatment-related changes (1)
- tumor progression (1)
- x-ray techniques (1)
Institute
- Physik (879)
- Frankfurt Institute for Advanced Studies (FIAS) (809)
- Informatik (775)
- Informatik und Mathematik (3)
- Medizin (3)
- Hochschulrechenzentrum (2)
- Biochemie und Chemie (1)
- ELEMENTS (1)
- Extern (1)
- Sportwissenschaften (1)
Coherent photoproduction of ρ⁰ vector mesons in ultra-peripheral Pb-Pb collisions at √sNN = 5.02 TeV
(2020)
Cross sections for the coherent photoproduction of ρ0 vector mesons in ultra-peripheral Pb-Pb collisions at sNN−−−√ = 5.02 TeV are reported. The measurements, which rely on the π+π− decay channel, are presented in three regions of rapidity covering the range |y| < 0.8. For each rapidity interval, cross sections are shown for different nuclear-breakup classes defined according to the presence of neutrons measured in the zero-degree calorimeters. The results are compared with predictions based on different models of nuclear shadowing. Finally, the observation of a coherently produced resonance-like structure with a mass around 1.7 GeV/c2 and a width of about 140 MeV/c2 is reported and compared with similar observations from other experiments.
The electron-capture process was studied for Xe54+ colliding with H2 molecules at the internal gas target of the Experimental Storage Ring (ESR) at GSI, Darmstadt. Cross-section values for electron capture into excited projectile states were deduced from the observed emission cross section of Lyman radiation, being emitted by the hydrogenlike ions subsequent to the capture of a target electron. The ion beam energy range was varied between 5.5 and 30.9 MeV/u by applying the deceleration mode of the ESR. Thus, electron-capture data were recorded at the intermediate and, in particular, the low-collision-energy regime, well below the beam energy necessary to produce bare xenon ions. The obtained data are found to be in reasonable qualitative agreement with theoretical approaches, while a commonly applied empirical formula significantly overestimates the experimental findings.
In particle collider experiments, elementary particle interactions with large momentum transfer produce quarks and gluons (known as partons) whose evolution is governed by the strong force, as described by the theory of quantum chromodynamics (QCD). These partons subsequently emit further partons in a process that can be described as a parton shower which culminates in the formation of detectable hadrons. Studying the pattern of the parton shower is one of the key experimental tools for testing QCD. This pattern is expected to depend on the mass of the initiating parton, through a phenomenon known as the dead-cone effect, which predicts a suppression of the gluon spectrum emitted by a heavy quark of mass mQ and energy E, within a cone of angular size mQ/E around the emitter. Previously, a direct observation of the dead-cone effect in QCD had not been possible, owing to the challenge of reconstructing the cascading quarks and gluons from the experimentally accessible hadrons. We report the direct observation of the QCD dead cone by using new iterative declustering techniques to reconstruct the parton shower of charm quarks. This result confirms a fundamental feature of QCD. Furthermore, the measurement of a dead-cone angle constitutes a direct experimental observation of the non-zero mass of the charm quark, which is a fundamental constant in the standard model of particle physics.
At particle collider experiments, elementary particle interactions with large momentum transfer produce quarks and gluons (known as partons) whose evolution is governed by the strong force, as described by the theory of quantum chromodynamics (QCD). The vacuum is not transparent to the partons and induces gluon radiation and quark pair production in a process that can be described as a parton shower. Studying the pattern of the parton shower is one of the key experimental tools in understanding the properties of QCD. This pattern is expected to depend on the mass of the initiating parton, through a phenomenon known as the dead-cone effect, which predicts a suppression of the gluon spectrum emitted by a heavy quark of mass m and energy E, within a cone of angular size m/E around the emitter. A direct observation of the dead-cone effect in QCD has not been possible until now, due to the challenge of reconstructing the cascading quarks and gluons from the experimentally accessible bound hadronic states. We report the first direct observation of the QCD dead-cone by using new iterative declustering techniques to reconstruct the parton shower of charm quarks. This result confirms a fundamental feature of QCD, which is derived more generally from its origin as a gauge quantum field theory. Furthermore, the measurement of a dead-cone angle constitutes a direct experimental observation of the non-zero mass of the charm quark, which is a fundamental constant in the standard model of particle physics.
Georg Büchners Fragment gebliebenes Drama "Woyzeck" (1837/1879) stellt eine Figur mit selbigem Namen ins Zentrum, die meint, Stimmen zu hören. Nicht nur leidet Woyzeck an akustischen Halluzinationen, diese drängen ihn zudem zu einer Mordtat, für die er schließlich hingerichtet werden soll. Von den diversen akustischen Halluzinationen, die im Clarus-Gutachten auftauchen, greift Büchner allerdings nur eine spezifische Konstellation heraus und montiert sie in sein Stück. Dessen ungeachtet zeigen dort die pietistischen Konventionen, die Sittenstrenge und die im Sprachbewusstsein eingelassenen Imperative eine eigentümliche Gewalt: Sie durchsetzen die Figurenrede, geben sich darin als Rede eines Anderen zu erkennen und können unabsehbare Impulse auslösen. Die gehörten Stimmen operieren dann gleich Vektoren, die einander begegnen oder durchdringen, was sogleich Handlungsketten durchtrennt und neu arrangieren lässt. Das trifft allerdings nicht nur auf die Hauptfigur zu, auch die übrigen Akteurinnen und Akteure zeigen sich von sozialen Imperativen durchherrscht, die einer eigenen Logik folgen. Die nachstehenden Überlegungen beabsichtigen, den Stimmen im Drama "Woyzeck" in bislang unversuchter Weise Gehör zu schenken. Wohl ist das Drama mitsamt der darin versammelten Stimmen Gegenstand unterschiedlicher Analysen geworden. Davon sich absetzend soll im Folgenden gezeigt werden, welche sprachstrukturellen Merkmale die herrschende Ideologie zeitigt, an welchen Stellen es ihr gelingt, ihre Subjekte anzurufen und wo sie fehlgeht - und schließlich soll ein bislang unentdeckt gebliebener Zusammenhang von Anrufung und den akustischen Halluzinationen Woyzecks zur Reflexion gebracht werden. Das wird in insgesamt vier Schritten geschehen, die jeweils theoretische Argumente begleiten, die den Arbeiten Louis Althussers und Jaques Lacans entnommen sind. Dieser Weg erlaubt eine Reflexion auf das im Drama angelegte Arsenal der Stimmen, mit dem zugleich eine spezifische Logik der Herrschaft zur Darstellung gebracht ist. Erstens wird die Funktion der Ideologie im Drama unter dem Aspekt der Anrufung untersucht. Zweitens wird das Misslingen der Anrufung an der Figur Woyzecks nachverfolgt, der auf ein davon abseitiges Genießen verfällt. Drittens wird daraus resultierend der Wahn als Installation einer anderen, psychotischen Anrufung erfasst. Und viertens wird anhand des wahnhaften Stimmenhörens eine metaleptische Reflexion im Drama aufgezeigt, welche die Funktion der Ideologie mit der Aufführungspraxis kombiniert.