K. Fransson
A5022381064- Quantum Chromodynamics and Particle Interactions
- Particle physics theoretical and experimental studies
- Nuclear physics research studies
- High-Energy Particle Collisions Research
- Particle Detector Development and Performance
- Nuclear Physics and Applications
- Atomic and Molecular Physics
- Particle accelerators and beam dynamics
- Superconducting Materials and Applications
- Radiation Detection and Scintillator Technologies
- Particle Accelerators and Free-Electron Lasers
- Quantum, superfluid, helium dynamics
- Atomic and Subatomic Physics Research
- Dark Matter and Cosmic Phenomena
- X-ray Spectroscopy and Fluorescence Analysis
- Advanced Chemical Physics Studies
- Medical Imaging Techniques and Applications
- Advanced NMR Techniques and Applications
- Neutrino Physics Research
- Advanced X-ray and CT Imaging
- Electron and X-Ray Spectroscopy Techniques
- Nuclear reactor physics and engineering
- CCD and CMOS Imaging Sensors
- Radioactive Decay and Measurement Techniques
- Rare-earth and actinide compounds
Uppsala University
2012-2021
University of Giessen
2016-2017
Forschungszentrum Jülich
2015
University of Tübingen
2014
Stockholm University
1986-2010
The University of Texas at Austin
1994
Lund University
1991-1992
Institut de Physique
1985
Nordic Institute for Theoretical Physics
1965-1984
European Organization for Nuclear Research
1978
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....
The ABC effect-a puzzling low-mass enhancement in the pipi invariant mass spectrum, first observed by Abashian, Booth, and Crowe-is well known from inclusive measurements of two-pion production nuclear fusion reactions. Here we report on exclusive kinematically complete most basic double-pionic reaction pn-->dpi;{0}pi;{0} at beam energies 1.03 1.35 GeV. measurements, which have been carried out CELSIUS-WASA, reveal effect to be a (pipi)_{I=L=0} channel phenomenon associated with both...
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...
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...
The quasifree $p+n\ensuremath{\rightarrow}d+\ensuremath{\eta}$ reaction cross section has been measured at the threshold using 1295 MeV protons in CELSIUS storage ring and an internal cluster-jet deuterium target. kinematics is chosen such that target proton can be assumed to a spectator. Fermi momentum of neutron used extract energy dependence by reconstructing on event-by-event basis. data cover excess energies from 10 center mass final $d\ensuremath{\eta}$ system. Approaching enhanced...
The quasifree p+n→d+η reaction cross section has been measured in the near-threshold region using deuterium from an internal cluster-jet target and 1350 MeV protons CELSIUS storage ring of Svedberg Laboratory, Uppsala. energy dependence is extracted by exploiting Fermi momentum neutron reconstructing kinematics on event-by-event basis. data cover center mass excess energies 16 to 113 MeV.Received 14 April 1997DOI:https://doi.org/10.1103/PhysRevLett.79.2642©1997 American Physical Society
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 pp-->pp pi(+) pi(-) reaction has been measured exclusively near threshold at CELSIUS. total cross sections are nearly an order of magnitude lower than expected from previous inclusive measurements. differential reveal pp-->pp(*)(1440)-->pp sigma = pp(pi(+)pi(-))(I l 0) as the dominant process well significant contributions p(*)-->Delta(++)pi(-)-->psigma. observed anisotropy in proton angular dependence is consistent with heavy-meson exchange. In invariant mass spectra, no narrow...