Speaker
Description
The A2 Collaboration at the Mainz Microtron MAMI measures photon absorption
cross sections using circularly and linearly polarized ’Bremsstrahlung’
photons up to an energy of 1.5 GeV and a polarized Frozen Spin Target. We
use a 4 π detection system with the ’Crystal Ball’ as central part.
One important experimental topic is the investigation of the baryons excitation
spectrum. Measurements with both longitudinally and transversely
polarized protons and deuterons are essential to disentangle the broad and
overlapping resonances. Several recently published data for single and double
polarization observables will be presented.
We have started a new program to measure double polarized Compton scattering
in a wide kinematic range, which will allow for the determination of
the ’Spin Polarizibilities’. As a technical highlight in this challenge we have
used an active polarized proton target in our dilution refrigerator in June
2016 for the first time.
