A5027924062- Particle physics theoretical and experimental studies
- Quantum Chromodynamics and Particle Interactions
- High-Energy Particle Collisions Research
- Nuclear physics research studies
- Particle Detector Development and Performance
- Radiation Detection and Scintillator Technologies
- Atomic and Subatomic Physics Research
- Nuclear Physics and Applications
- Dark Matter and Cosmic Phenomena
- Particle Accelerators and Free-Electron Lasers
- Quantum, superfluid, helium dynamics
- Advanced NMR Techniques and Applications
- Superconducting Materials and Applications
- Particle accelerators and beam dynamics
- Atomic and Molecular Physics
- Neutrino Physics Research
- Magnetic confinement fusion research
- Medical Imaging Techniques and Applications
- Nuclear reactor physics and engineering
- Advanced Data Storage Technologies
- Heat Transfer and Boiling Studies
- Spacecraft and Cryogenic Technologies
- Pulsars and Gravitational Waves Research
- Advanced Chemical Physics Studies
- Scientific Computing and Data Management
GSI Helmholtz Centre for Heavy Ion Research
1997-2025
Ruhr University Bochum
2015-2024
National and Kapodistrian University of Athens
2023-2024
Laboratoire de Physique des 2 Infinis Irène Joliot-Curie
2024
Institut National de Physique Nucléaire et de Physique des Particules
2024
Université Paris-Saclay
2024
Centre National de la Recherche Scientifique
2024
Forschungszentrum Jülich
2014-2023
University of California, Riverside
2023
Old Dominion University
2020-2022
We have analyzed data of the DISTO experiment on exclusive pp -> p Lambda K+ reaction at 2.85 GeV to search for a strongly bound compact K-pp (= X) state be formed in + X reaction. The observed spectra missing-mass and invariant-mass with high transverse momenta revealed broad distinct peak mass M_X = 2265 +- 2 (stat) 5 (syst) MeV/c2 width Gamma_X 118 8 10 MeV.
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...
Four different combinations of 4496Ru and 4096Zr nuclei, both as projectile target, were investigated at the same bombarding energy 400AMeV using a 4π detector. The degree isospin mixing between target nucleons is mapped across large portion phase space two isospin-tracer observables, number measured protons tritium to 3He yield ratio. experimental results show that global equilibrium not reached even in most central collisions. Quantitative measures stopping are extracted from data. They...
The photon decay of the relativistic Coulomb excitation single and double giant dipole resonance (GDR) in target has been observed system 1A GeV $^{209}\mathrm{Bi}$ on $^{208}\mathrm{Pb}$. For peripheral events which are dominated by excitation, a large Lorentzian structure energy spectrum is peaked at 13.3\ifmmode\pm\else\textpm\fi{}0.1 MeV with width 4.1\ifmmode\pm\else\textpm\fi{}0.1 MeV, corresponding to GDR $^{208}\mathrm{Pb}$ target. sum coincident...
The invariant-mass spectrum of $e^+ e^-$ pairs produced in $^{12}$C+$^{12}$C collisions at an incident energy 2 GeV per nucleon has been measured for the first time. pair production probabilities span over five orders magnitude from $\pi^0$-Dalitz to $\rho/\omega$ region. Dalitz decays $\pi^0$ and $\eta$ account all yield up 0.15 GeV/c$^2$, but only about 50% above this mass. A comparison with model calculations shows that excess is likely due baryon-resonance vector-meson decays. Transport...
Total and differential cross sections for the dp→He3η reaction have been measured near threshold He3 center-of-mass momenta in range from 17.1 MeV/c to 87.5 MeV/c. The data were taken during a slow ramping of COSY internal deuteron beam scattered on proton target detecting ejectiles with COSY-11 facility. forward–backward asymmetries deviate clearly zero above 50 indicating presence higher partial waves final state. Below fit state enhancement factor total results He3–η scattering length...
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 exclusive production cross sections for ω and φ mesons have been measured in proton-proton reactions at plab=3.67 GeV/c. observed φ/ω section ratio is (3.8±0.2−0.9+1.2)×10−3. After phase space corrections, this enhanced by about an order of magnitude relative to naive predictions based upon the Okubo-Zweig-Iizuka (OZI) rule, comparison enhancement a factor ∼3 previously higher beam momenta. modest increase near threshold compared much larger specific channels p¯p annihilation...
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...
Taking advantage of both the high mass resolution COSY-11 detector and energy low-emittance proton beam cooler synchrotron COSY, we determine excitation function for pp→ppη(') reaction close to threshold. Combining these data with previous results, extract scattering length η(')-proton potential in free space be Re(a(pη(')))=0±0.43 fm Im(a(pη(')))=0.37(-0.16)(+0.40) fm.
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 azimuthal angle distributions of neutral pions at midrapidity from Au+Au reactions 1 GeV/nucleon incident energy have been measured. An enhanced emission π0's perpendicular to the reaction plane is observed. asymmetry dependent on π0 momentum: spectrum harder than in plane. strength observed appears be more pronounced for charged particles and neutrons.Received 29 April 1993DOI:https://doi.org/10.1103/PhysRevLett.71.835©1993 American Physical Society
We have studied the reaction $p+$$^{27}\mathrm{Al}$ $\ensuremath{\rightarrow}$ $^{3}\mathrm{He}$$+p+{\ensuremath{\pi}}^{\ensuremath{-}}+X$ at recoil-free kinematics. An $\ensuremath{\eta}$ meson possibly produced in this would be thus almost rest laboratory system and could therefore bound with high probability, if nuclear states exist. The decay of such a state through ${N}^{*}(1535)$ resonance lead to proton-${\ensuremath{\pi}}^{\ensuremath{-}}$ pair emitted opposite directions. For these...