T. Kloiber
A5016132275- Quantum Chromodynamics and Particle Interactions
- Particle physics theoretical and experimental studies
- High-Energy Particle Collisions Research
- Physics of Superconductivity and Magnetism
- Luminescence Properties of Advanced Materials
- Black Holes and Theoretical Physics
- Theoretical and Computational Physics
- Cold Atom Physics and Bose-Einstein Condensates
- Inorganic Fluorides and Related Compounds
- Advanced Chemical Physics Studies
- Atomic and Subatomic Physics Research
- Quantum many-body systems
- Quantum, superfluid, helium dynamics
- Quantum and electron transport phenomena
- Radiation Detection and Scintillator Technologies
- Noncommutative and Quantum Gravity Theories
- Advanced NMR Techniques and Applications
- Cosmology and Gravitation Theories
- Quantum Mechanics and Applications
- Advanced Condensed Matter Physics
- Particle Accelerators and Free-Electron Lasers
- Strong Light-Matter Interactions
- Advanced Semiconductor Detectors and Materials
- Inorganic Chemistry and Materials
- Electronic and Structural Properties of Oxides
University of Regensburg
2015-2017
North Carolina State University
2016-2017
University of Graz
2012-2017
Deutsches Elektronen-Synchrotron DESY
1985-1992
Universität Hamburg
1985-1991
University of Florence
1988-1990
SLAC National Accelerator Laboratory
1985-1987
Carnegie Mellon University
1987
Cracow University of Technology
1987
Friedrich-Alexander-Universität Erlangen-Nürnberg
1987
The reaction ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}{e}^{+}{e}^{\ensuremath{-}}{\ensuremath{\pi}}^{0}{\ensuremath{\pi}}^{0}$ has been analyzed using 97 ${\mathrm{pb}}^{\ensuremath{-}1}$ of data taken with the Crystal Ball detector at DESY ${e}^{\ensuremath{-}}{e}^{+}$ storage ring DORIS II beam energies around 5.3 GeV. For first time we have measured cross section for $\ensuremath{\gamma}\ensuremath{\gamma}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{0}{\ensuremath{\pi}}^{0}$...
We derive an exact representation of the massless Schwinger model on lattice in terms dual variables which are configurations loops, dimers and plaquette occupation numbers. When expressed with partition sum has only real positive also when a chemical potential or topological term added -- situations where conventional complex action problem. The allows for Monte Carlo simulations without restrictions values vacuum angle.
We derive dual representations for O(N) and CP(N-1) models on the lattice. In terms of variables partition sums have only real positive contributions also at finite chemical potential. Thus complex action problem conventional formulation is overcome using Monte Carlo simulations are possible arbitrary
The reaction \ensuremath{\gamma}\ensuremath{\gamma}\ensuremath{\rightarrow}${\ensuremath{\pi}}^{0}$\ensuremath{\eta} has been investigated with the Crystal Ball detector at DESY storage ring DORIS II. Formation of \ensuremath{\delta}(980) and ${A}_{2}$(1320) observed \ensuremath{\gamma}\ensuremath{\gamma} partial widths ${\ensuremath{\Gamma}}_{\ensuremath{\gamma}\ensuremath{\gamma}}$(${A}_{2}$)=1.14\ifmmode\pm\else\textpm\fi{}0.20\ifmmode\pm\else\textpm\fi{}0.2 6 keV...
Abstract Desorption of neutral atoms following selective excitonic excitation with low energy electrons or synchrotron radiation underlines the crucial role exciton–lattice interaction in microscopic desorption mechanisms. All rare gas solids yield ground state which stem from relaxation molecular-type trapped excitations after their radiative decay. In addition, solid Ne and Ar metastables, 3P1 1P1 atoms. The excited is a consequence negative work function. It closely related to exciton...
The two-dimensional U(1) gauge-Higgs model with a topological term is simple example of lattice field theory where the complex action problem comes from term. We show that can be exactly rewritten in terms dual variables, such partition sum has only real and positive contributions. Using suitable algorithms formulation allows for Monte Carlo simulations at arbitrary values vacuum angle. demonstrate feasibility simulation study continuum limit, as well phase diagram system.
The Crystal Ball detector has been used at the DORIS II storage ring DESY to study reaction ${\mathit{e}}^{+}$${\mathit{e}}^{\mathrm{\ensuremath{-}}}$\ensuremath{\rightarrow}${\mathit{e}}^{+}$${\mathit{e}}^{\mathrm{\ensuremath{-}}}$\ensuremath{\gamma}*\ensuremath{\gamma}*\ensuremath{\rightarrow}${\mathit{e}}^{+}$${\mathit{e}}^{\mathrm{\ensuremath{-}}}$\ensuremath{\gamma}\ensuremath{\gamma}, where X is a narrow resonance with mass between 100 and 3000 MeV. Formation of...
We discuss the thermodynamics of O(3) nonlinear sigma model in 1+1 dimensions at nonzero chemical potential (equivalent to a magnetic field). In its conventional field theory representation suffers from sign problem. By dualizing lattice we present, for first time, density data an asymptotically free with dynamical mass-gap. find quantum phase transition zero temperature where as function assumes value. present evidence corresponding critical exponent z close 2. The low energy is conjectured...
Desorption of neutral rare gas atoms following selective excitonic excitation solids (Ne, Ar, Kr, Xe) by VUV photons underlines the crucial role excitons concerning (i) transport energy from bulk to surface, and (ii) microscopic desorption mechanism itself. All yield ground state which stem relaxation molecular-type after their radiative decay. In addition, solid Ne Ar 3P1, 1P1, metastable (3P2, 3P0) atoms. Total yields as well partial excited will be presented. The dominating primary...
This letter reports the first total and partial PSD-yields of neutral atoms from solid Ne which were obtained combining mass-spectroscopic with photoluminescence techniques. Exciton trapping as an intrinsic property exciton-phonon interaction is important source desorption. Trapping at surface favours excited-atom
The inclusive photon spectrum in hadronic decays of the $\ensuremath{\Upsilon}(2S)$ is measured with Crystal Ball detector at DORIS II. Four well separated lines, which are consistent decay hypothesis $\ensuremath{\Upsilon}(2S)\ensuremath{\rightarrow}\ensuremath{\gamma}+^{3}P_{2,1,0}$ and $^{3}P_{2,1}\ensuremath{\rightarrow}\ensuremath{\gamma}\ensuremath{\Upsilon}(1S)$, observed. energies lines from primary transitions...
We show that information about scattering data of a quantum field theory can be obtained from studying the system at finite density and low temperatures. In particular we consider models formulated on lattice exactly dualized to theories conserved charge fluxes links. Apart eliminating complex action problem nonzero chemical potential $\ensuremath{\mu}$, these dualizations allow for particle world line interpretation dual which one extract two-particle wave function. As an example perform...
The reaction ${e}^{+}$${e}^{\mathrm{\ensuremath{-}}}$\ensuremath{\rightarrow}${e}^{+}$${e}^{\mathrm{\ensuremath{-}}}$\ensuremath{\eta}${\ensuremath{\pi}}^{0}$${\ensuremath{\pi}}^{0}$ has been observed with the Crystal Ball detector at DORIS II storage ring DESY. \ensuremath{\eta}${\ensuremath{\pi}}^{0}$${\ensuremath{\pi}}^{0}$ mass spectrum is dominated by \ensuremath{\eta}', and two-photon width...
We have investigated the hadronic transitions \ensuremath{\Upsilon}(2S)\ensuremath{\rightarrow}${\ensuremath{\pi}}^{0}$${\ensuremath{\pi}}^{0}$\ensuremath{\Upsilon}(1S)\ensuremath{\rightarrow}\ensuremath{\gamma}\ensuremath{\gamma}\ensuremath{\gamma}\ensuremath{\gamma}l +${l}^{\mathrm{\ensuremath{-}}}$ (l=\ensuremath{\mu} or e) and...