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- Al Jebali, Ramsey, et al.
(author)
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A helium gas scintillator active target for photoreaction measurements
- 2015
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In: European Physical Journal A. Hadrons and Nuclei. - : Springer Science and Business Media LLC. - 1434-6001. ; 51:10
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Journal article (peer-reviewed)abstract
- A multi-cell He gas scintillator active target, designed for the measurement of photoreaction cross sections, is described. The target has four main chambers, giving an overall thickness of 0.103 g/cm(3) at an operating pressure of 2MPa. Scintillations are read out by photomultiplier tubes and the addition of small amounts of N-2 to the He, to shift the scintillation emission from UV to visible, is discussed. First results of measurements at the MAX IV Laboratory tagged-photon facility show that the target has a timing resolution of around 1 ns and can cope well with a high-flux photon beam. The determination of reaction cross sections from target yields relies on a Monte Carlo simulation, which considers scintillation light transport, photodisintegration processes in He-4, background photon interactions in target windows and interactions of the reaction-product particles in the gas and target container. The predictions of this simulation are compared to the measured target response.
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3. |
- Terschlusen, Carla, et al.
(author)
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Low-lying pseudoscalar and vector mesons and their dynamics : How to describe radiative reactions with an odd number of pions
- 2014
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In: INPC 2013 - International Nuclear Physics Conference, Vol. 2. - : EDP Sciences. - 9782759811762 ; , s. 06023-
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Conference paper (peer-reviewed)abstract
- In chiral perturbation theory, the leading-order contribution to reactions with pions in the sector of odd intrinsic parity is defined by the Wess-Zumino-Witten structure. This structure is supplemented by a simple vector-meson Lagrangian where the vector mesons are described by antisymmetric tensor fields. With the rho-omega-pion coupling as the only parameter in the sector of odd intrinsic parity, i.e. without additional contact terms, one can achieve a proper description of the single- and double-virtual pion transition form factor and the three-pion production in electron-positron collisions.
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4. |
- Terschlüsen, Carla, et al.
(author)
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Reactions with pions and vector mesons in the sector of odd intrinsic parity
- 2014
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In: Menu 2013 - 13Th International Conference Meson-Nucleon Physics And The Structure Of The Nucleon. - : EDP Sciences.
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Conference paper (peer-reviewed)abstract
- In chiral perturbation theory, the leading-order contribution to reactions with pions in the sector of odd intrinsic parity is defined by the Wess-Zumino-Witten structure. This structure is supplemented by a simple vector-meson Lagrangian where the vector mesons are described by antisymmetric tensor fields. With the rho-omega-pion coupling as the only parameter in the sector of odd intrinsic parity, i.e. without additional contact terms, one can achieve a proper description of the pion transition form factor and the three-pion production in electron-positron collisions.
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5. |
- Terschlüsen, Carla, et al.
(author)
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Reactions with pions and vector mesons in the sector of odd intrinsic parity
- 2013
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In: European Physical Journal A. - : Springer Science and Business Media LLC. - 1434-6001 .- 1434-601X. ; 49:9, s. 116-
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Journal article (peer-reviewed)abstract
- TheWess-Zumino-Witten structure is supplemented by a simple vector-meson Lagrangian where the vector mesons are described by antisymmetric tensor fields. With the rho-omega-pi coupling as the only parameter in the sector of odd intrinsic parity, i.e. without additional contact terms, one can achieve a proper description of the decay of an omega-meson into three pions, the single-and double-virtual pion transition form factor and the three-pion production in electron-positron collisions.
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