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Title: Baryon spectroscopy: Recent results from the Crystal Barrel/TAPS experiment at ELSA

To understand the spectrum and the properties of baryon resonances, the CBELSA/TAPS experiment at ELSA investigates the photoproduction of single- and multi-meson final states off the nucleon. In the latter final states baryon cascades via Dp and Dh and also via higher mass baryon resonances are clearly observed. A partial wave analysis based on single and double meson photoproduction data as well as data from other reactions allows a first determination of resonance properties including partial decay widths of various N* and {Delta}* states. Those include also the decays into the different p{pi}{sup 0{pi}0} and p{pi}{sup 0{eta}} decay channels resulting partly in unexpected results. Recently not only single but also double polarisation experiments have been performed, which are absolutelly necessary to resolve ambiguities in the partial wave analyses (PWA) used to extract the resonances from the data; without the measurement of polarisation observables a model-independent PWA will not be possible. Polarisation observables have been investigated using linearly, circularly polarized or unpolarized photons impinging on an longitudinally polarized or unpolarized target. Given the angular coverage of the Crystal-Barrel/TAPS experiment this data cover almost the full angular range and phase space. This data will provide key information for the partial wave analysesmore » and brings us one step closer towards the needed complete experiment.« less
Authors:
 [1]
  1. Helmholtz-Institut fuer Strahlen- und Kernphysik, Universitaet Bonn (Germany)
Publication Date:
OSTI Identifier:
21426376
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: 10.1063/1.3483315; (c) 2010 American Institute of Physics
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; BARYON SPECTROSCOPY; DELTA BARYONS; ETA MESONS; MULTIPARTICLE SPECTROMETERS; NUCLEONS; PARTIAL WAVES; PARTICLE DECAY; PARTICLE IDENTIFICATION; PHASE SPACE; PHOTON-NUCLEON INTERACTIONS; PHOTONS; PHOTOPRODUCTION; POLARIZATION; QUANTUM CHROMODYNAMICS; QUARK MODEL; RESONANCE PARTICLES BARYONS; BASIC INTERACTIONS; BOSONS; COMPOSITE MODELS; DECAY; ELECTROMAGNETIC INTERACTIONS; ELEMENTARY PARTICLES; FERMIONS; FIELD THEORIES; HADRONS; INTERACTIONS; MASSLESS PARTICLES; MATHEMATICAL MODELS; MATHEMATICAL SPACE; MEASURING INSTRUMENTS; MESONS; N*BARYONS; PARTICLE INTERACTIONS; PARTICLE MODELS; PARTICLE PRODUCTION; PHOTON-BARYON INTERACTIONS; PHOTON-HADRON INTERACTIONS; PSEUDOSCALAR MESONS; QUANTUM FIELD THEORY; SPACE; SPECTROMETERS; SPECTROSCOPY