Speaker
Dr
Anselm Esser
(Inst. f. Kernphysik / Uni Mainz)
Description
Beam-normal single-spin asymmetry in the elastic scattering of electrons is a direct probe for the two photon exchange.
At the Mainz Mictrotron, this asymmetry has been measured for Carbon-12 at a Q² of 0.04 GeV². A 570 MeV continuous wave electrons beam was scattered on a carbon target and detected by two magnetic spectrometers. Quartz glass cherenkov detectors located at the elastic line in the spectrometer's focal plane were used to measure the amount of scattered electrons. The PMTs of which were read out with integrating current ADCs allowing for particle rates too high for counting.
The resulting asymmetry shows a surprising deviation from theoretical predictions.
Primary author
Dr
Anselm Esser
(Inst. f. Kernphysik / Uni Mainz)