V. Hejny

ORCID: 0000-0003-0713-5859
Publications
Citations
Views
---
Saved
---
About
Contact & Profiles
Research Areas
  • 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
  • Radiation Detection and Scintillator Technologies
  • Quantum, superfluid, helium dynamics
  • Particle Accelerators and Free-Electron Lasers
  • Advanced NMR Techniques and Applications
  • Dark Matter and Cosmic Phenomena
  • Particle Detector Development and Performance
  • Atomic and Molecular Physics
  • Markov Chains and Monte Carlo Methods
  • Magnetic confinement fusion research
  • Medical Imaging Techniques and Applications
  • Magnetic properties of thin films
  • Scientific Computing and Data Management
  • Particle accelerators and beam dynamics
  • Cold Atom Physics and Bose-Einstein Condensates
  • Stochastic processes and statistical mechanics
  • Computational Physics and Python Applications
  • Nuclear reactor physics and engineering
  • Inorganic Fluorides and Related Compounds
  • Electron Spin Resonance Studies

Forschungszentrum Jülich
2014-2024

Uppsala University
2017-2020

Jagiellonian University
2012

Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Frascati
2012

Dr. Margarete Fischer-Bosch-Institute of Clinical Pharmacology
2007

Stadtwerke Jülich (Germany)
2003

University of Giessen
1995-2001

Giessen School of Theology
1995

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....

10.1103/physrevlett.106.242302 article EN Physical Review Letters 2011-06-17

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...

10.1103/physrevlett.112.202301 article EN Physical Review Letters 2014-05-23

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...

10.1103/physrevlett.98.242301 article EN Physical Review Letters 2007-06-13

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...

10.1103/physrevc.88.055208 article EN Physical Review C 2013-11-26

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...

10.1103/physrevc.90.035204 article EN publisher-specific-oa Physical Review C 2014-09-15

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...

10.1016/j.physletb.2015.02.067 article EN cc-by Physics Letters B 2015-03-03

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...

10.1103/physrevlett.115.094801 article EN publisher-specific-oa Physical Review Letters 2015-08-26

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.

10.1103/physrevlett.117.054801 article EN publisher-specific-oa Physical Review Letters 2016-07-28

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.

10.1016/j.physletb.2010.10.050 article EN cc-by Physics Letters B 2010-10-28

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...

10.1103/physrevc.87.035204 article EN Physical Review C 2013-03-08

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...

10.1103/physrevx.13.031004 article EN cc-by Physical Review X 2023-07-12

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...

10.48550/arxiv.2501.19123 preprint EN arXiv (Cornell University) 2025-01-31

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,...

10.1103/physrevlett.119.014801 article EN Physical Review Letters 2017-07-05

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.

10.1140/epja/i2016-16147-5 article EN cc-by The European Physical Journal A 2016-05-01

The photon asymmetry in the reaction 1H(--> gamma,pi(0))(1)H close to threshold has been measured for first time with spectrometer TAPS using linearly polarized photons from tagged-photon facility at Mainz Microtron MAMI. total and differential cross sections were also simultaneously asymmetry. This allowed determination of S-wave all three P-wave amplitudes. values obtained are E(0+) = [-1.33+/-0.08(stat)+/-0.03(syst)] x 10(-3)/m(pi(+)), P(1) [9.47 +/- 0.08(stat) 0.29(syst)]...

10.1103/physrevlett.87.232501 article EN Physical Review Letters 2001-11-15
Coming Soon ...