A5018607503- Quantum Chromodynamics and Particle Interactions
- Particle physics theoretical and experimental studies
- High-Energy Particle Collisions Research
- Nuclear physics research studies
- Quantum, superfluid, helium dynamics
- Atomic and Subatomic Physics Research
- Black Holes and Theoretical Physics
- Quantum chaos and dynamical systems
- Cold Atom Physics and Bose-Einstein Condensates
- Advanced NMR Techniques and Applications
- Physics of Superconductivity and Magnetism
- Quantum Electrodynamics and Casimir Effect
- Cosmology and Gravitation Theories
- Dark Matter and Cosmic Phenomena
- Scientific Research and Discoveries
- Computational Physics and Python Applications
- Noncommutative and Quantum Gravity Theories
- Superconducting Materials and Applications
- Quantum Mechanics and Applications
- Mechanical and Optical Resonators
- Nonlinear Photonic Systems
- Particle Accelerators and Free-Electron Lasers
- Nonlinear Waves and Solitons
- Magnetic properties of thin films
- Advanced Chemical Physics Studies
Forschungszentrum Jülich
2012-2024
Uppsala University
2018
University of California, Santa Barbara
2017
University of Bonn
2004-2005
Stadtwerke Jülich (Germany)
2005
Stony Brook University
1982-2000
Technical University of Darmstadt
1995-1999
Darmstadt University of Applied Sciences
1993-1996
University of Saskatchewan
1996
Novo Nordisk (Denmark)
1987-1993
We present a simple formalism for the evaluation of Casimir energy two spheres and sphere plane, in case scalar fluctuating field, valid at any separations. compare exact results with various approximation schemes establish when such become useful. The can be easily extended to number and/or planes three or arbitrary dimensions, variety boundary conditions nonoverlapping potentials/nonideal reflectors.
We show that the proposed measurements of electric dipole moments light nuclei in storage rings would put strong constraints on models flavor-diagonal CP violation. Our analysis is exemplified by a comparison Standard Model including QCD theta term, minimal left-right symmetric model, specific version so called aligned two-Higgs doublet and briefly supersymmetric extension Model. By using effective field theory techniques we demonstrate to what extent nucleons, deuteron, helion could...
We provide a consistent and complete calculation of the electric dipole moments deuteron, helion, triton in framework chiral effective field theory. The CP-conserving CP-violating interactions are treated on equal footing we consider one-, two-, three-nucleon operators up to next-to-leading-order power counting. In particular, calculate for first time EDM contributions induced by three-pion operator. find that effects nucleon-nucleon contact larger than those found previous studies based...
A new method to determine the spin tune is described and tested. In an ideal planar magnetic ring, tune-defined as number of precessions per turn-is given by ν(s)=γG (γ Lorentz factor, G gyromagnetic anomaly). At 970 MeV/c, deuteron spins coherently precess at a frequency ≈120 kHz in Cooler Synchrotron COSY. The deduced from up-down asymmetry deuteron-carbon scattering. time interval 2.6 s, was determined with precision order 10^{-8}, 1×10^{-10} for continuous 100 s accelerator cycle. This...
An extension of the Gutzwiller trace formula is given that includes diffraction effects due to hard wall scatterers or other singularities. The new involves periodic orbits which have arcs on surface singularity and correspond creeping waves. A family resonances in two-disk scattering system can be well described completely missing if only traditional are used.
We extend the Skyrme model to incorporate vector mesons $\ensuremath{\rho}$ and $\ensuremath{\omega}$ in a way consistent with non-Abelian anomalies of QCD vector-meson dominance. The are treated as composite gauge bosons hidden ${\mathrm{SU}(2)}_{V}\ensuremath{\bigotimes}\mathrm{U}(1)$ symmetry. investigate bulk properties hedgehog-type solitons baryon number $B=1$ sector this model.
Based on the notion that local dark-matter field of axions or axionlike particles (ALPs) in our Galaxy induces oscillating couplings to spins nucleons and nuclei (via electric dipole moment latter and/or paramagnetic axion-wind effect), we establish feasibility a new method search for ALPs storage rings. previous work allows us maintain in-plane polarization stored deuteron beam few hundred seconds, perform first proof-of-principle experiment at Cooler Synchrotron (COSY) scan momenta near...
This paper presents the successful application of a phase-lock feedback system to maintain resonance condition radio frequency (rf) spin rotator (specifically, an rf Wien filter) with respect 120 kHz precession in Cooler Synchrotron (COSY) storage ring. Real-time monitoring and filter signal allows relative phase between two be stabilized at arbitrary setpoint. The compensates for deviations by adjusting and/or as needed. With this method, variation demand standard deviation...
We discuss the Overhauser effect (particle-hole pairing) versus BCS (particle-particle or hole-hole in QCD at large quark density. In weak coupling and to leading logarithm accuracy, pairing energies can be estimated exactly. For a small number of colors, overtakes effect, while for colors opposite takes place, agreement with recent renormalization group argument. strong energies, may dominant any suggesting that crystallize into an insulator few times nuclear matter density, situation...
We calculate the branching ratios of yet unmeasured eta' decays into four pions, based on a combination chiral perturbation theory and vector-meson dominance. The --> 2(pi+ pi-) pi+ pi- 2pi0 are P-wave dominated can largely be thought to proceed via two rho resonances; we predict fractions (1.0+-0.3)*10^-4 (2.4+-0.7)*10^-4, respectively, not much lower than current experimental upper limits. 4pi0 eta 4pi0, in contrast, D-wave driven as long conservation CP symmetry is assumed, significantly...
We argue that high-quality data on the reaction $e^+e^-\to π^+π^-η$ will allow one to determine doubly-virtual form factor $η\to γ^*γ^*$ in a model-independent way with controlled accuracy. This is an important step towards reliable evaluation of hadronic light-by-light scattering contribution anomalous magnetic moment muon. When analyzing existing for $e^+e^-\toπ^+π^-η$ total energies squared $k^2>1\text{GeV}^2$, we demonstrate effect $a_2$ meson provides natural breaking mechanism...
The quest for new sources of the simultaneous violation $C$ and $CP$ symmetry was popular in 1960s has since been mostly neglected more than half a century. In this work we revisit fundamental quark-level operators that break up to including mass dimension 8 flavor-conserving transitions, relying on complete operator sets so-called Standard Model effective field theory low-energy theory. With formalism chiral perturbation theory, match these quark light-meson physics, derive $C$- $CP$-odd...