I. Keshelashvili
A5005268838- Quantum Chromodynamics and Particle Interactions
- Particle physics theoretical and experimental studies
- Nuclear physics research studies
- High-Energy Particle Collisions Research
- Atomic and Subatomic Physics Research
- Nuclear Physics and Applications
- Advanced NMR Techniques and Applications
- Particle Detector Development and Performance
- Radiation Detection and Scintillator Technologies
- Particle Accelerators and Free-Electron Lasers
- Dark Matter and Cosmic Phenomena
- Quantum, superfluid, helium dynamics
- Particle accelerators and beam dynamics
- Magnetic confinement fusion research
- X-ray Spectroscopy and Fluorescence Analysis
- Superconducting Materials and Applications
- Atomic and Molecular Physics
- Computational Physics and Python Applications
- Advanced Chemical Physics Studies
- Neutrino Physics Research
- Advanced Data Storage Technologies
- Mechanical and Optical Resonators
- Quantum and electron transport phenomena
- Distributed and Parallel Computing Systems
- Scientific Research and Discoveries
Forschungszentrum Jülich
2014-2024
University of Basel
2011-2021
Johannes Gutenberg University Mainz
2017-2020
Saint Mary's University
2018
Justus-Liebig-Universität Gießen
2013-2015
University of Glasgow
2015
University of Edinburgh
2015
Tbilisi State University
2004-2013
Crystal Research (United States)
2011
P.N. Lebedev Physical Institute of the Russian Academy of Sciences
2010
To study fundamental questions of hadron and nuclear physics in interactions antiprotons with nucleons nuclei, the universal PANDA detector will be built. Gluonic excitations, strange charm quarks nucleon structure studies performed unprecedented accuracy thereby allowing high-precision tests strong interaction. The proposed is a state-of-the art internal target at HESR FAIR detection identification neutral charged particles generated within relevant angular energy range. This report...
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...
The pp→pK+Y0 reaction has been studied for hyperon masses m(Y0)⩽1540MeV/c2 at COSY-Jülich by using a 3.65 GeV/c circulating proton beam incident on an internal hydrogen target. Final states comprising two protons, one positively charged kaon and negatively pion have identified with the ANKE spectrometer. Such configurations are sensitive to production of ground state Λ Σ0 hyperons as well Σ0(1385) Λ(1405) resonances. Applying invariant- missing-mass techniques, overlapping excited could be...
The gp-->etap reaction has been measured with the Crystal Ball and TAPS multiphoton spectrometers in energy range from production threshold of 707 MeV to 1.4 GeV (1.49 =< W >= 1.87 GeV). Bremsstrahlung photons produced by 1.5-GeV electron beam Mainz Microtron MAMI-C momentum analyzed Glasgow Tagging Spectrometer were used for eta-meson production. Our accumulation 3.8 x 10^6 gp-->etap-->3pi0p-->6gp events allows a detailed study dynamics. differential cross sections determined 120 bins full...
This document describes the technical layout and expected performance of Straw Tube Tracker (STT), main tracking detector $\overline{P}$ ANDA target spectrometer. The STT encloses a Micro-Vertex-Detector (MVD) for inner is followed in beam direction by set GEM stations. tasks are measurement particle momentum from reconstructed trajectory specific energy loss identification. Dedicated simulations with full analysis studies certain proton-antiproton reactions, identified as being benchmark...
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...
We observe a deuteron beam polarization lifetime near 1000 s in the horizontal plane of magnetic storage ring (COSY). This long spin coherence time is maintained through combination bunching, electron cooling, sextupole field corrections, and suppression collective effects current limits. record required for search an intrinsic electric dipole moment on at statistical sensitivity level approaching 10^{-29} e cm.
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.
The first measurement is reported of the double-polarization observable G in photoproduction neutral pions off protons, covering photon energy range from 620 to 1120 MeV and full solid angle. describes correlation between polarization plane scattering for protons polarized along direction incoming photon. highly sensitive contributions baryon resonances. new results are compared predictions SAID, MAID, BnGa partial wave analyses. In spite long-lasting efforts understand γp→pπ0 as simplest...
Measurements of $γp \rightarrow K^{+} Λ$ and Σ^0$ cross-sections have been obtained with the photon tagging facility Crystal Ball calorimeter at MAMI-C. The measurement uses a novel $K^+$ meson identification technique in which weak decay products are characterized using energy timing characteristics deposit calorimeter, method that has potential to be applied many other facilities. fine center-of-mass ($W$) resolution statistical accuracy new data results significant impact on partial wave...
Differential and total cross sections for the quasifree reactions $\gamma p\rightarrow\eta p$ n\rightarrow\eta n$ have been determined at MAMI-C electron accelerator using a liquid deuterium target. Photons were produced via bremsstrahlung from 1.5 GeV incident beam energy-tagged with Glasgow photon tagger. Decay photons of neutral decay modes $\eta\rightarrow 2\gamma$ 3\pi^0 \rightarrow 6\gamma$ coincident recoil nucleons detected in combined setup Crystal Ball TAPS calorimeters. The...
The first measurement of the helicity dependence photoproduction cross section single neutral pions off protons is reported for photon energies from 600 to 2300 MeV, covering nearly full solid angle. data are compared predictions SAID, MAID, and BnGa partial wave analyses. Strikingly large differences between observed, which traced in amplitudes well-known established resonances. Precise values several resonances reported.
An experimental study of $\omega$ photoproduction on the proton was conducted by using Crystal Ball and TAPS multiphoton spectrometers together with photon tagging facility at Mainz Microtron MAMI. The $\gamma p\to\omega p$ differential cross sections are measured from threshold to incident-photon energy $E_\gamma=1.40$ GeV ($W=1.87$ for center-of-mass energy) 15-MeV binning in $E_\gamma$ full production-angle coverage. quality present data near gives access a variety interesting physics...
The reactions γp→ηp and γp→η^{'}p are measured from their thresholds up to the center-of-mass energy W=1.96 GeV with tagged-photon facilities at Mainz Microtron, MAMI. Differential cross sections obtained unprecedented statistical accuracy, providing fine binning full production-angle coverage. A strong cusp is observed in total section for η photoproduction energies vicinity of η^{'} threshold, W=1896 MeV (E_{γ}=1447 MeV). Within framework a revised ηMAID isobar model, cusp, connection...
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...
The photoproduction of η mesons off nucleons bound in 2H and 3He has been measured coincidence with recoil protons neutrons for incident photon energies from threshold up to 1.4 GeV. experiments were performed at the Mainz MAMI accelerator, using Glasgow tagged facility. Decay photons η→2γ η→3π0 decays detected an almost 4π electromagnetic calorimeter combining Crystal Ball TAPS detectors. data both targets are excellent statistical quality show a narrow structure excitation function γn→nη....
The Dalitz decay $\ensuremath{\eta}\ensuremath{\rightarrow}{e}^{+}{e}^{\ensuremath{-}}\ensuremath{\gamma}$ has been measured in the $\ensuremath{\gamma}p\ensuremath{\rightarrow}\ensuremath{\eta}p$ reaction with Crystal Ball and TAPS multiphoton spectrometers, together photon-tagging facility at Mainz Microtron MAMI. experimental statistic used this work is one order of magnitude greater than any previous measurement...