Speaker
Marcus Gruener
(Helmholtz-Institut für Strahlen- und Kernphysik)
Description
The excitation spectrum of the nucleon consists of several overlapping resonances. To identify these resonances, and their contributions to the measured cross sections, a partial wave analysis is used. One needs at least a set of eight, well chosen, single and double polarisation observables to give an unambiguous solution. With the Crystal Barrel/TAPS setup at ELSA, single and double polarisation observables can be measured, by using a combination of a linearly or circularly polarised photon beam and a longitudinally or transversely polarised butanol frozen spin target. In this talk the results of the measurement of the double polarisation observable G in the reactions \vec{\gamma} \vec{p} \to p \pi^0 and \vec{\gamma} \vec{p} \to p \eta are presented. This pro ject is supported by the DFG (SFB/TR16).
Primary author
Marcus Gruener
(Helmholtz-Institut für Strahlen- und Kernphysik)
