A5029218659- Quantum Chromodynamics and Particle Interactions
- Particle physics theoretical and experimental studies
- High-Energy Particle Collisions Research
- Nuclear physics research studies
- Particle Accelerators and Free-Electron Lasers
- Atomic and Molecular Physics
- Particle accelerators and beam dynamics
- Nuclear Physics and Applications
- Quantum and electron transport phenomena
- X-ray Spectroscopy and Fluorescence Analysis
- Advanced NMR Techniques and Applications
- Magnetic confinement fusion research
- Theoretical and Computational Physics
- Advanced Chemical Physics Studies
- Electron and X-Ray Spectroscopy Techniques
- High-pressure geophysics and materials
- Muon and positron interactions and applications
- Neutrino Physics Research
- Superconducting Materials and Applications
- Physics of Superconductivity and Magnetism
- Quantum many-body systems
- Laser-induced spectroscopy and plasma
- Quantum chaos and dynamical systems
- Quantum, superfluid, helium dynamics
- Dark Matter and Cosmic Phenomena
Forschungszentrum Jülich
2006-2017
Duke University
2017
Ruhr University Bochum
2008-2011
Campbell Collaboration
2009
Hebrew University of Jerusalem
1987-2006
Goethe University Frankfurt
1991-2006
Max Planck Institute of Quantum Optics
2004
Ludwig-Maximilians-Universität München
2004
Stadtwerke Jülich (Germany)
1988-2003
Max Planck Institute for Nuclear Physics
2003
The differential and total cross sections for the dp→3Heη reaction have been measured in a high precision statistics COSY-ANKE experiment near threshold using continuous beam energy ramp up to an excess Q of 11.3 MeV with essentially 100% acceptance. kinematics allowed mean value be determined about 9 keV. Evidence is found effects higher partial waves Q≳4 MeV. very rapid rise section its maximum within 0.5 implies large η3He scattering length hence presence quasibound state extremely close...
In the very heavy collision system $^{197}\mathrm{Au}$${+}^{197}$Au ${\mathit{K}}^{+}$ production process was studied as a function of impact parameter at 1 GeV/nucleon, beam energy well below free N-N threshold. The multiplicity increases more than linearly with number participant nucleons and ${\mathit{K}}^{+}$/${\mathrm{\ensuremath{\pi}}}^{+}$ ratio rises significantly when going from peripheral to central collisions. measured double differential cross section is enhanced by factor 6...
Type Ia supernovae (SNe Ia) are thought to be thermonuclear explosions of massive white dwarfs (WDs). We present the first study multidimensional effects during final hours prior runaway that leads explosion. The calculations utilize an implicit, two-dimensional hydrodynamic code. Mixing and ignition process studied in detail. find initial chemical structure WD is changed, but material not fully homogenized. In particular, exploding sustains a central region with low C/O ratio. This implies...
The production of phi mesons in the collisions 2.83 GeV protons with C, Cu, Ag, and Au at forward angles has been measured via -> K+K- decay using COSY-ANKE magnetic spectrometer. meson cross section follows a target mass dependence A^0.56+/-0.02 momentum region 0.6-1.6 GeV/c. comparison data model calculations suggests that in-medium width is about an order magnitude larger than its free value.
Transitions between the rotational states J = 1 and 0 densities of phonon libron are investigated by incoherent inelastic neutron scattering at 4.2 1.15°K for several concentrations c ortho component. By extrapolation observed c-dependent energy state to effective quadrupole-quadrupole coupling constant is determined. The observations on compared theoretical predictions.
Triple differential cross sections d3σ/dp3 for charged pions produced in symmetric heavy-ion collisions were measured with the KaoS magnetic spectrometer at synchrotron facility SIS GSI. The correlations between momentum vectors of and reaction plane 197Au+197Au an incident energy 1 GeV/nucleon determined. We observe, first time, azimuthally anisotropic distribution pions, enhanced emission perpendicular to plane. anisotropy is most pronounced high transverse semicentral collisions.Received...
A new and simple method is developed for calculating effective interactions produced by interaction between electronic configurations. Also, a classification of the effective-interaction operators performed, which both generalizes corrects previous made Bacher Goudsmit.
The pp->pp phi reaction has been studied at the Cooler Synchrotron COSY-Juelich, using internal beam and ANKE facility. Total cross sections have determined three excess energies epsilon near production threshold. differential section closest to threshold epsilon=18.5 MeV exhibits a clear S-wave dominance as well noticeable effect due proton-proton final state interaction. Taken together with data for pp omega-production, significant enhancement of phi/omega ratio factor 8 is found compared...
The differential and total cross sections for kaon pair production in the pp->ppK+K- reaction have been measured at three beam energies of 2.65, 2.70, 2.83 GeV using ANKE magnetic spectrometer COSY-Juelich accelerator. These near-threshold data are separated into pairs arising from decay phi-meson remainder. For non-phi selection, ratio terms K-p K+p invariant masses is strongly peaked towards low masses. This effect can be described quantitatively by a simple ansatz final state...
Large differences have been found in the x-ray yields produced by 22.5- and 48-MeV iodine ions incident on solid ($_{34}\mathrm{Se}$) gaseous ($_{35}\mathrm{Br}$ $_{36}\mathrm{Kr}$) targets. These are attributable to steady-state excitation of penetrating ion prior vacancy producing collision, yield information state energetic solids.
650 levels belonging to the configurations (3d + 4s)n of all second spectra iron group were calculated, and 472 observed fitted them. In addition usually used approximation, a complete set two-body three-body effective-interaction parameters between 3d electrons was also introduced. Using only effective interactions, we obtained mean error ±192 cm−1; while interactions reduced ±87 cm−1.
The production of $\ensuremath{\varphi}$ mesons in proton collisions with C, Cu, Ag, and Au targets has been studied via the $\ensuremath{\varphi}\ensuremath{\rightarrow}{K}^{+}{K}^{\ensuremath{-}}$ decay at an incident beam energy 2.83 GeV using ANKE detector system COSY. For first time, momentum dependence nuclear transparency ratio, in-medium width, differential cross section for $\ensuremath{\varphi}$-meson forward angles have determined these over range 0.6--1.6 GeV/$c$. There are...
The quasifree $pn\ensuremath{\rightarrow}d\ensuremath{\phi}$ reaction has been studied at the Cooler Synchrotron COSY---J\"ulich, using internal proton beam incident on a deuterium cluster-jet target and detecting fast deuteron in coincidence with ${K}^{+}{K}^{\ensuremath{-}}$ decay of $\ensuremath{\phi}$ meson. energy dependence total differential cross sections are extracted for excess energies up to 80 MeV by determining Fermi momentum neutron an event-by-event basis. Though these...
A sample of ${K}^{+}$ mesons stopped in the CERN 1.1-${\mathrm{m}}^{3}$ heavy-liquid bubble chamber has been used to study Dalitz-plot density and ${\ensuremath{\mu}}^{+}$ polarization ${{K}_{\ensuremath{\mu}3}}^{+}$ decay measure ${{K}_{e3}}^{+}$ branching ratios. All three analyses are described detail, they used, separately combined, form strangeness-changing, semileptonic weak interaction. This is found be consistent with a coupling vector currents invariant under time reversal. The...
Differential and total cross sections for the pp -> ppK+K- reaction have been measured at a proton beam energy of 2.83 GeV using COSY-ANKE magnetic spectrometer. Detailed model descriptions fitted to variety one-dimensional distributions permit separation phi section from that non-phi production. The differential spectra show higher partial waves represent majority an excess 76 MeV, whose dependence would then seem require some s-wave phi-p enhancement near threshold. data can be described...
The pp -> ppK+K- reaction was measured below the phi threshold at a beam energy of 2.568 GeV using COSY-ANKE magnetic spectrometer. By assuming that four-body phase space is distorted only by product two-body final state interactions, fits to variety one-dimensional distributions permit evaluation differential and total cross sections. shapes in Kp Kpp invariant masses are reproduced if K-p interaction even stronger than found higher energy. cusp effect K+K- distribution K0K0bar much more...