RECENT RESULTS FROM THE REAL PHOTON EXPERIMENT AT MAMI

Abstract

Experiments with real photons have been performed for many years at the Mainz accelerator MAMI with different detectors. The upgraded MAMI C accelerator recently delivered electrons with an energy of 1604MeV. The A2 collaboration performs experiments with energy tagged polarised real photons produced via 'Bremsstrahlung'. Linear and circular photon polarisation is possible. In the years 2005/2006 the Crystal Ball detector with its unique detection capability for multi photon final states was set up in Mainz. The Crystal Ball at MAMI setup offers an excellent possibility to study decays of the η and η′ mesons. Due to the high intensity photon beam the apparatus can be seen as an η-factory. Recent results from the Crystal Ball experiment at MAMI are presented. In the future we plan to use a longitudinal and transverse polarised frozen spin target to investigate the spin polarisibilities of the nucleons.