Parts | Days | Selection | Search | Downloads | Help

HK: Hadronen und Kerne

HK 26: Electromagnetic Probes IV, Electro-, Photoproduction

HK 26.6: Talk

Tuesday, March 17, 1998, 15:30–15:45, B

Measurement of the photon asymmetry for the production of neutral pions on the proton in the threshold region^* — •A. Schmidt — Institut für Kernphysik, Universität Mainz, Johann–Joachim–Becher–Weg 45, D–55099 Mainz

Photoproduction of neutral pions on the proton using linearly polarized photons has been measured in the energy range close to threshold at the Mainz Microtron MAMI as a further test of Chiral Pertubation Theory (ChPT). Linearly polarized photons were obtained by using the Glasgow–Mainz tagger with a diamond crystal as a radiator. Neutral pions were identified via their 2γ–decay with TAPS, a detector system consisting of 504 individual BaF₂– scintillators.
The measurement of the photon asymmetry for the production of neutral pions in the threshold region allows to separate the s–wave amplitude E₀₊ and all p–wave amplitudes. The ChPT Low–Energy–Theorem for the p–waves will be compared to first experimental results.

^* supported by Deutsche Forschungsgemeinschaft (SFB 201)