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Title: Recent Results from Experiments at COSY

Abstract

In hadron physics, experiments using hadronic probes may shed light on open questions on the structure of hadrons, their interactions that are subject to the strong force and on the symmetries of nature. Therefore a major focus of the physics program studied at the COoler SYnchrotron COSY of the Forschungszentrum Juelich is the production of mesons and hyperons in hadron- hadron scattering with the aim to investigate relevant production processes, interactions of the participating particles as well as symmetries and symmetry breaking. The COoler SYnchrotron COSY at Juelich accelerates protons and deuterons with momenta up to 3.7 GeV/c covering hadron physics in the light quark sector. The availability of the beam cooling systems allow precision measurements, using polarized proton and deuteron beams in combination with polarized Hydrogen or Deuterium targets. Due to the excellent experimental conditions at COSY single- and double-polarization measurements can be performed with high reaction rates. With the operation of the recently installed WASA-at-COSY apparatus, high-statistics studies aiming at rare decays of {eta} and {eta}{sup '} are effectively turning COSY into a meson factory. This contribution summarizes the ongoing physics program at the COSY facility, using the detector systems ANKE, WASA and COSY-TOF highlighting a few selectivemore » recent results and outlining future developments. The research at COSY also provides a step towards the realization of FAIR with studies on spin manipulation and polarization build-up of protons in polarized targets.« less

Authors:
 [1]
  1. Institutfuer Kernphysik and Juelich Centre for Hadron Physics, Forschungszentrum Juelich, D-52425 Juelich (Germany)
Publication Date:
OSTI Identifier:
21426382
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 1257; Journal Issue: 1; Conference: HADRON 2009: 13. international conference on hadron spectroscopy, Tallahassee, FL (United States), 29 Nov - 4 Dec 2009; Other Information: DOI: 10.1063/1.3483321; (c) 2010 American Institute of Physics
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; COSY STORAGE RING; D QUARKS; DEUTERIUM TARGET; DEUTERON BEAMS; ETA MESONS; GEV RANGE; MULTIPARTICLE SPECTROMETERS; NUCLEAR REACTION KINETICS; NUCLEON-NUCLEON INTERACTIONS; PARTICLE DECAY; PARTICLE IDENTIFICATION; PARTICLE PRODUCTION; POLARIZATION; POLARIZED BEAMS; POLARIZED TARGETS; SPIN; STRONG INTERACTIONS; SYMMETRY BREAKING; U QUARKS; ACCELERATORS; ANGULAR MOMENTUM; BARYON-BARYON INTERACTIONS; BASIC INTERACTIONS; BEAMS; BOSONS; CYCLIC ACCELERATORS; DECAY; ELEMENTARY PARTICLES; ENERGY RANGE; FERMIONS; HADRON-HADRON INTERACTIONS; HADRONS; INTERACTIONS; ION BEAMS; KINETICS; MEASURING INSTRUMENTS; MESONS; PARTICLE INTERACTIONS; PARTICLE PROPERTIES; PSEUDOSCALAR MESONS; QUARKS; REACTION KINETICS; SPECTROMETERS; STORAGE RINGS; SYNCHROTRONS; TARGETS

Citation Formats

Goldenbaum, Frank. Recent Results from Experiments at COSY. United States: N. p., 2010. Web. doi:10.1063/1.3483321.
Goldenbaum, Frank. Recent Results from Experiments at COSY. United States. doi:10.1063/1.3483321.
Goldenbaum, Frank. Thu . "Recent Results from Experiments at COSY". United States. doi:10.1063/1.3483321.
@article{osti_21426382,
title = {Recent Results from Experiments at COSY},
author = {Goldenbaum, Frank},
abstractNote = {In hadron physics, experiments using hadronic probes may shed light on open questions on the structure of hadrons, their interactions that are subject to the strong force and on the symmetries of nature. Therefore a major focus of the physics program studied at the COoler SYnchrotron COSY of the Forschungszentrum Juelich is the production of mesons and hyperons in hadron- hadron scattering with the aim to investigate relevant production processes, interactions of the participating particles as well as symmetries and symmetry breaking. The COoler SYnchrotron COSY at Juelich accelerates protons and deuterons with momenta up to 3.7 GeV/c covering hadron physics in the light quark sector. The availability of the beam cooling systems allow precision measurements, using polarized proton and deuteron beams in combination with polarized Hydrogen or Deuterium targets. Due to the excellent experimental conditions at COSY single- and double-polarization measurements can be performed with high reaction rates. With the operation of the recently installed WASA-at-COSY apparatus, high-statistics studies aiming at rare decays of {eta} and {eta}{sup '} are effectively turning COSY into a meson factory. This contribution summarizes the ongoing physics program at the COSY facility, using the detector systems ANKE, WASA and COSY-TOF highlighting a few selective recent results and outlining future developments. The research at COSY also provides a step towards the realization of FAIR with studies on spin manipulation and polarization build-up of protons in polarized targets.},
doi = {10.1063/1.3483321},
journal = {AIP Conference Proceedings},
number = 1,
volume = 1257,
place = {United States},
year = {Thu Aug 05 00:00:00 EDT 2010},
month = {Thu Aug 05 00:00:00 EDT 2010}
}
  • WASA--a 4{pi} spectrometer for detection of charged and neutral particles--started operation at the cooler synchrotron COSY-Juelich in 2007. A number of experiments on meson production and decays have been carried out since then. The status of the analysis and preliminary results of some selected topics from the physics program are discussed.
  • Studies of light meson decays are the key experiments for the WASA detector at COSY-Juelich. One of the world largest data samples of the {eta} meson decays have been recently collected in the pd {yields}{sup 3}He{eta} and in the pp {yields} pp{eta} reactions. The status of the analysis of various decay channels and the further plans for the light meson decay program are presented.
  • The structure of d(AC){sub 4}{center dot}d(GT){sub 4} is investigated by constrained molecular dynamics simulations. The constraints include proton pair distances derived from 2D NOE intensities by using the iterative relaxation matrix analysis algorithm MARDIGRAS and sugar pucker phases and amplitudes derived from double-quantum-filtered COSY spectra. Molecular dynamics runs on simulated intensity and distance sets as well as the experimental data were carried out to determine the effects of starting structure, distance constraint derivation, energy functions, and experimental errors on the end result. It was found that structural details could not be elucidated within about 1.5-{angstrom} overall atomic deviation. This limitationmore » is due in part to the accuracy of the experimental data but, more importantly, is attributable to the quantity of experimental constraints available and to imperfections in the force field utilized in the molecular dynamics calculations. Within the limits of the method, some structural characteristics of d(AC){sub 4}{center dot}d(GT){sub 4} could be elucidated.« less
  • ICRF has been applied at power levels up to of 4 MW for plasma heating with good results in the L- and H-modes, alone and in combination with NI. Mainly minority heating has been applied so far, in some cases combined with second harmonic. Modulation experiments allowed to determine the power absorption efficiency, deposition profiles and the local heat conduction. The ICRF was also shown to have further interesting and beneficial effects on the plasma: the central impurity concentration of tungsten injected by Laser Blow Off was reduced, and a transiently improved energy confinement at the beginning of the NBImore » pulse was stabilized. The influence of plasma variations on the RF system and methods allowing stable operation, e.g. during the ELMy H-mode, were studied. Coupling measurements were also used to examine SOL characteristics. Experiments comparing antennas with and without Faraday screen show only minor differences of their electrical properties and heating characteristics. {copyright} {ital 1996 American Institute of Physics.}« less