A. Kacharava
A5077664712- Nuclear physics research studies
- Quantum Chromodynamics and Particle Interactions
- Particle physics theoretical and experimental studies
- Atomic and Subatomic Physics Research
- High-Energy Particle Collisions Research
- Nuclear Physics and Applications
- Advanced NMR Techniques and Applications
- Particle Accelerators and Free-Electron Lasers
- Quantum, superfluid, helium dynamics
- Atomic and Molecular Physics
- Dark Matter and Cosmic Phenomena
- Particle accelerators and beam dynamics
- Superconducting Materials and Applications
- Advanced Data Storage Technologies
- Radiation Detection and Scintillator Technologies
- Scientific Research and Discoveries
- Particle Detector Development and Performance
- Scientific Computing and Data Management
- Neutrino Physics Research
- Nuclear reactor physics and engineering
- X-ray Spectroscopy and Fluorescence Analysis
- Magnetic confinement fusion research
- Electron Spin Resonance Studies
- Advanced Chemical Physics Studies
- Distributed and Parallel Computing Systems
Forschungszentrum Jülich
2014-2024
University of Ferrara
2012
Joint Institute for Nuclear Research
1989-2012
Tbilisi State University
2001-2012
Petersburg Nuclear Physics Institute
2009-2012
Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Frascati
2012
Friedrich-Alexander-Universität Erlangen-Nürnberg
2002-2009
University of Cologne
2009
Campbell Collaboration
2005-2009
Osaka University
2001
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...
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.
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...
This Letter reports the successful use of feedback from a spin polarization measurement to revolution frequency $0.97\text{ }\text{ }\mathrm{GeV}/c$ bunched and polarized deuteron beam in Cooler Synchrotron (COSY) storage ring order control both precession rate ($\ensuremath{\approx}121\text{ }\mathrm{kHz}$) phase horizontal component. Real time synchronization with radio (rf) solenoid made possible rotation out plane, yielding demonstration method manipulate polarization. In particular,...
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...
This paper describes a time-marking system that enables measurement of the in-plane (horizontal) polarization 0.97-GeV/c deuteron beam circulating in Cooler Synchrotron (COSY) at Forschungszentrum J\"ulich. The clock time each polarimeter event is used to unfold 120-kHz spin precession and assign events bins according direction horizontal polarization. After accumulation for one or more seconds, down-up scattering asymmetry can be calculated matched sinusoidal function whose magnitude...
The stable spin direction of polarized particles in a storage ring was determined first experimentally, through an accurate measurement the tune and its response to longitudinal magnetic fields.
The deuteron tensor analysing power T20 of the d→p→He3η reaction has been measured at COSY-ANKE facility in small steps excess energy Q up to Q=11 MeV. Despite square production amplitude varying by over a factor five through this range, shows little dependence. This is evidence that final state interaction causing variation not influenced spin configuration entrance channel. weak angular dependence observed for provides useful insight into structure near threshold.
We report on measurements of the differential cross section $d\ensuremath{\sigma}/d\mathrm{\ensuremath{\Omega}}$ and first measurement analyzing power ${A}_{y}$ in $\mathrm{\ensuremath{\Delta}}(1232)$ excitation energy region reaction $pp\ensuremath{\rightarrow}{{pp}}_{s}{\ensuremath{\pi}}^{0}$ where ${{pp}}_{s}$ is a $^{1}S_{0}$ proton pair. The experiment has been performed with ANKE spectrometer at COSY-J\"ulich. data reveal peak dependence forward section, minimum zero degrees its...
The proposed method exploits charged particles confined as a storage ring beam (proton, deuteron, possibly $^3$He) to search for an intrinsic electric dipole moment (EDM) aligned along the particle spin axis. Statistical sensitivities could approach 10$^{-29}$ e$\cdot$cm. challenge will be reduce systematic errors similar levels. adjusted preserve polarisation, initially parallel velocity, times in excess of 15 minutes. Large radial fields, acting through EDM, rotate polarisation from...
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...
Polarized antiprotons can be produced in a storage ring by spin-dependent interaction purely electron-polarized hydrogen gas target. The polarizing process is based on spin transfer from the polarized electrons of target atoms to orbiting antiprotons. After filtering for about two beam lifetimes at energies $T\ensuremath{\approx}40--170\text{ }\text{ }\mathrm{M}\mathrm{e}\mathrm{V}$ using dedicated large acceptance ring, antiproton polarization would reach $P=0.2--0.4$. open new and unique...
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...
The vector and tensor polarizations of a deuteron beam have been measured using elastic deuteron-carbon scattering at 75.6 MeV deuteron-proton 270 MeV. After acceleration to 1170 inside the COSY ring, deuterons were checked by studying variety nuclear reactions cluster target ANKE magnet spectrometer placed an internal position storage ring. All these measurements consistent with absence depolarization during provide number secondary standards that can be used in subsequent experiments facility.
The differential and total cross sections for the $\mathit{dp}\ensuremath{\rightarrow}^{3}\mathrm{He}\ensuremath{\eta}$ reaction have been measured at COSY--ANKE excess energies of 19.5, 39.4, 59.4 MeV over full angular range. results are in line with trends apparent from detailed near-threshold studies also largely agree those CELSIUS, though present data much better coverage near forward backward directions, thus allowing firmer conclusions to be drawn. While 19.5 can described terms $s$-...
The paper describes the commissioning of experimental equipment and machine studies required for first spin-filtering experiment with protons at a beam kinetic energy 49.3 MeV in COSY. implementation low-$\ensuremath{\beta}$ insertion made it possible to achieve lifetimes ${\ensuremath{\tau}}_{b}=8000\text{ }\text{ }\mathrm{s}$ presence dense polarized hydrogen storage-cell target areal density...