A5021654900- Particle physics theoretical and experimental studies
- Quantum Chromodynamics and Particle Interactions
- High-Energy Particle Collisions Research
- Atomic and Subatomic Physics Research
- Particle Accelerators and Free-Electron Lasers
- X-ray Diffraction in Crystallography
- Crystallization and Solubility Studies
- Particle accelerators and beam dynamics
- Atomic and Molecular Physics
- Dark Matter and Cosmic Phenomena
- Particle Detector Development and Performance
- Quantum, superfluid, helium dynamics
- Magnetic confinement fusion research
- Advanced NMR Techniques and Applications
- Nuclear Physics and Applications
- Nuclear physics research studies
- Superconducting Materials and Applications
- X-ray Spectroscopy and Fluorescence Analysis
- Cold Atom Physics and Bose-Einstein Condensates
- Crystallography and Radiation Phenomena
- Magnetic properties of thin films
- Advanced X-ray Imaging Techniques
- Solar and Space Plasma Dynamics
- Neutrino Physics Research
- Advanced Chemical Physics Studies
Forschungszentrum Jülich
2015-2025
GSI Helmholtz Centre for Heavy Ion Research
2023
RWTH Aachen University
2023
Stadtwerke Jülich (Germany)
2022
Friedrich-Alexander-Universität Erlangen-Nürnberg
2010-2020
Argonne National Laboratory
2019
Istituto Nazionale di Fisica Nucleare, Sezione di Bari
2016
Ernst Ruska Centre
2014
Joint Institute for Nuclear Research
2007-2012
University of Ferrara
2012
Azimuthal single-spin asymmetries of lepto-produced pions and charged kaons were measured on a transversely polarized hydrogen target. Evidence for naive-T-odd, transverse-momentum-dependent parton distribution function is deduced from non-vanishing Sivers effects pi+, pi0, K+, K-, as well in the difference pi+ pi- cross sections.
Single-spin asymmetries for pions and charged kaons are measured in semi-inclusive deep-inelastic scattering of positrons electrons off a transversely nuclear-polarized hydrogen target. The dependence the cross section on azimuthal angles target polarization (phi_S)and produced hadron (phi) is found to have substantial sin(phi+phi_S) modulation production pi+, pi- K+. This Fourier component can be interpreted terms non-zero transversity distribution functions favored disfavored Collins...
Multiplicities in semi-inclusive deep-inelastic scattering are presented for each charge state of ${\ensuremath{\pi}}^{\ifmmode\pm\else\textpm\fi{}}$ and ${\mathrm{K}}^{\ifmmode\pm\else\textpm\fi{}}$ mesons. The data were collected by the HERMES experiment at HERA storage ring using 27.6 GeV electron positron beams incident on a hydrogen or deuterium gas target. results as function kinematic quantities ${x}_{\mathrm{B}}$, ${Q}^{2}$, $z$, ${P}_{h\ensuremath{\perp}}$. They represent unique set...
The azimuthal cos{\phi} and cos2{\phi} modulations of the distribution hadrons produced in unpolarized semi-inclusive deep-inelastic scattering electrons positrons off hydrogen deuterium targets have been measured HERMES experiment. For first time these were determined a four-dimensional kinematic space for positively negatively charged pions kaons separately, as well unidentified hadrons. These dependences are sensitive to transverse motion polarization quarks within nucleon via, e.g.,...
Beam-helicity and beam-charge asymmetries in the hard exclusive leptoproduction of real photons from an unpolarised hydrogen target by a 27.6 GeV lepton beam are extracted HERMES data set 2006-2007 using missing-mass event selection technique. The asymmetry amplitudes this more precise than those earlier 1996-2005 previously analysed same manner HERMES. results two sets compatible with each other. Results these combined constitute most amplitude measurements made kinematic region
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.
A bstract The beam-helicity asymmetry in exclusive electroproduction of real photons by the longitudinally polarized Hera positron beam scattering off an unpolarized hydrogen target is measured at Hermes. arises from deeply virtual Compton and its interference with Bethe-Heitler process. Azimuthal amplitudes are extracted a data sample consisting ep → epγ events detection all particles final state including recoiling proton. installation recoil detector, while reducing acceptance experiment,...
Double-spin asymmetries in exclusive electroproduction of real photons from a transversely polarized hydrogen target are measured with respect to the product polarization beam helicity and charge, alone. The arise deeply virtual Compton scattering process its interference Bethe--Heitler process. They related part same combination form factors as that determining previously published transverse single-spin through imaginary part. results for double-spin found be compatible zero within...
A bstract comprehensive set of azimuthal single-spin and double-spin asymmetries in semi-inclusive leptoproduction pions, charged kaons, protons, antiprotons from transversely polarized protons is presented. These include the previously published HERMES results on Collins Sivers asymmetries, analysis which has been extended to also an extraction a three-dimensional kinematic binning enlarged phase space. They are complemented by corresponding for remaining four allowed one-photon-exchange...
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...
An inductive compact beam position monitor based on a segmented toroidal coil surrounding the charged particle has been investigated. It makes use of induced voltages in windings instead charge imbalance capacitor plates popular monitors. We theoretically investigate response coils to bunched lumped-element model and compare it measurements laboratory storage ring COSY terms displacement. As frequency coils, we find resonant behavior, which may be exploited further increase sensitivity...
Longitudinal double-spin asymmetries of charged hadrons with high transverse momentum p T have been measured in electroproduction using the Hermes detector at Hera. Processes involving gluons nucleon enhanced relative to others by selecting typically above 1 GeV. In this kinematic domain gluon polarization has extracted leading order making use model embedded Monte Carlo Generator Pythia 6.2. The obtained from single inclusive range GeV < 2.5 a deuterium target is $ \frac{{\Delta...
An earlier extraction from the HERMES experiment of polarization-averaged parton distribution strange quarks in nucleon has been reevaluated using final data on multiplicities charged kaons semi-inclusive deep-inelastic scattering obtained with a kinematically more comprehensive method correcting for experimental effects. General features are confirmed, but rise at low x is less pronounced than previously reported.
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,...
This letter of intent proposes an experiment to search for electric dipole moment the muon based on frozen-spin technique. We intend exploit high field, $E=1{\rm GV/m}$, experienced in rest frame with a momentum $p=125 {\rm MeV/}c$ when passing through large magnetic field $|\vec{B}|=3{\rm T}$. Current fluxes at $μ$E1 beam line permit improved sensitivity $σ(d_μ)\leq 6\times10^{-23}e{\rm cm}$, about three orders magnitude more than current upper limit $|d_μ|\leq1.8\times10^{-19}e{\rm...
The exclusive electroproduction of π+ mesons was studied with the HERMES spectrometer at DESY laboratory by scattering 27.6 GeV positron and electron beams off an internal hydrogen gas target. virtual-photon cross sections were measured as a function Mandelstam variable t squared four momentum −Q2 exchanged virtual photon. A model calculation based on Generalized Parton Distributions is in fair agreement data low values |t| if power corrections are included. Regge formalism gives good...
We report the first measurements of A_N absolute value and shape in -t range from 0.0015 to 0.010GeV/c^2 with a precision better than 0.005 for each data point using polarized atomic hydrogen gas jet target 100 GeV RHIC proton beam.
Exclusive electroproduction of pi+ mesons was studied by scattering 27.6 GeV positrons or electrons off a transversely polarized hydrogen target. The single-spin azimuthal asymmetry with respect to target polarization measured as function the Mandelstam variable t, Bjorken scaling x_B, and virtuality Q^2 exchanged photon. extracted Fourier components were found be consistent zero, except one that large involves interference contributions from longitudinal transverse virtual photons.