B. Lorentz
A5042412921- Quantum Chromodynamics and Particle Interactions
- Nuclear physics research studies
- Particle physics theoretical and experimental studies
- Particle Accelerators and Free-Electron Lasers
- Particle accelerators and beam dynamics
- Atomic and Subatomic Physics Research
- Advanced NMR Techniques and Applications
- Nuclear Physics and Applications
- High-Energy Particle Collisions Research
- Atomic and Molecular Physics
- Superconducting Materials and Applications
- Quantum, superfluid, helium dynamics
- Dark Matter and Cosmic Phenomena
- X-ray Spectroscopy and Fluorescence Analysis
- Particle Detector Development and Performance
- Magnetic confinement fusion research
- Crystallography and Radiation Phenomena
- Radiation Therapy and Dosimetry
- Scientific Computing and Data Management
- Electron Spin Resonance Studies
- Advanced Thermodynamic Systems and Engines
- Advanced Data Storage Technologies
- Advanced X-ray Imaging Techniques
- Gyrotron and Vacuum Electronics Research
- Geophysical and Geoelectrical Methods
GSI Helmholtz Centre for Heavy Ion Research
2020-2024
Forschungszentrum Jülich
2011-2020
Uppsala University
2017-2020
University of Bonn
2009-2017
University of Ferrara
2012
Joint Institute for Nuclear Research
2012
Tbilisi State University
2012
Petersburg Nuclear Physics Institute
2007-2012
Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Frascati
2012
University of Michigan–Ann Arbor
2004-2009
We report on an exclusive and kinematically complete high-statistics measurement of the basic double-pionic fusion reaction pn→dπ(0)π(0) over full energy region ABC effect, a pronounced low-mass enhancement in ππ-invariant mass spectrum. The measurements, which cover also transition to conventional t-channel ΔΔ process, were performed with upgraded WASA detector setup at COSY. data reveal Abashian-Booth-Crowe effect be uniquely correlated Lorentzian dependence integral cross section....
Exclusive and kinematically complete high-statistics measurements of quasifree polarized $\stackrel{\ensuremath{\rightarrow}}{n}p$ scattering have been performed in the energy region narrow resonancelike structure ${d}^{*}$ with $I({J}^{P})=0({3}^{+})$, $M\ensuremath{\approx}2380\text{ }\text{ }\mathrm{MeV}$, $\mathrm{\ensuremath{\Gamma}}\ensuremath{\approx}70\text{ }\mathrm{MeV}$ observed recently double-pionic fusion channels...
Exclusive measurements of the quasifree $pn\ensuremath{\rightarrow}pp{\ensuremath{\pi}}^{0}{\ensuremath{\pi}}^{\ensuremath{-}}$ reaction have been performed by means $pd$ collisions at ${T}_{p}$ $=$ 1.2 GeV using wide angle shower apparatus (WASA) detector setup cooler synchrotron COSY (Institut f\"ur Kernphysik, J\"ulich). Total and differential cross sections obtained covering energy region $\sqrt{s}$ (2.35--2.46) GeV, which includes ABC effect its associated resonance structure. No...
New data on quasifree polarized neutron-proton scattering in the region of recently observed ${d}^{*}$ resonance structure are obtained by exclusive and kinematically complete high-statistics measurements with WASA at COSY. This paper details determination beam polarization, checks character process, all ${A}_{y}$ angular distributions new partial-wave analysis, which includes producing a pole ${}^{3}{D}_{3}\ensuremath{-}{}^{3}{G}_{3}$ coupled partial waves...
Exclusive measurements of the quasi-free $np \to np\pi^0\pi^0$ reaction have been performed by means $dp$ collisions at $T_d$ = 2.27 GeV using WASA detector setup COSY. Total and differential cross sections obtained covering energy region $\sqrt s$ (2.35 - 2.46) GeV, which includes ABC effect its associated $d^*(2380)$ resonance. Adding $d^*$ resonance amplitude to that for conventional processes leads a reasonable description data. The observed in total section is agreement with predictions...
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 proton and deuteron analyzing powers ten of the possible 12 spin correlation coefficients have been measured for $p+d$ elastic scattering at bombarding energies 135 200 MeV. results are compared with Faddeev calculations using two different $\mathit{NN}$ potentials. qualitative features extensive data set on dependence in over a wide range angles presented here remarkably well explained by two-nucleon force predictions without inclusion three-nucleon force. remaining discrepancies are,...
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.
An exclusive measurement of the excitation function for dd->3Heppi- reaction was performed at Cooler Synchrotron COSY-Juelich with WASA-at-COSY detection system. The data were taken during a slow acceleration beam from 2.185 GeV/c to 2.400 crossing kinematic threshold eta meson production in dd->4He-eta 2.336 GeV/c. corresponding excess energy respect 4He-eta system varied -51.4MeV 22MeV. integrated luminosity experiment determined using dd->3Hen reaction. shape examined. No signal bound...
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 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,...
We report on a high-statistics measurement of the most basic double pionic fusion reaction $\vec{n}p \to d\pi^0\pi^0$ over energy region $d^*(2380)$ resonance by use polarized deuteron beam and observing in quasifree scattering mode. The measurements were performed with WASA detector setup at COSY. data reveal substantial analyzing powers confirm conclusions about $d^*$ obtained from unpolarized measurements. also previous under complementary kinematic conditions.
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.