https://doi.org/10.1140/epja/i2006-10428-6
PAVI 2006
Transverse single spin asymmetry at the A4 experiment
Preliminary backward-scattering results
Institut für Kernphysik, Johannes Gutenberg Universität, Mainz, Germany
* e-mail: capozza@kph.uni-mainz.de
Received:
31
August
2006
Accepted:
18
March
2007
Published online:
11
July
2007
The spin asymmetry in the scattering of transversely polarised electrons on unpolarised hydrogen target has been measured by the A4 Collaboration at backward-scattering angle. The square of the four-momentum transfer was Q 2 = 0.22 (GeV/c)^2 like in one of the previous measurements of the A4 Collaboration at forward angle. In this kinematical configuration the spin asymmetry is of the order of 100ppm and presents a very clear azimuthal angle dependency. Some preliminary results are presented and are in agreement with theoretical predictions. Also some details about the extraction of the asymmetry are given and the handling of the background is discussed.
PACS: 13.40.Gp Electromagnetic form factors – / 11.30.Er Charge conjugation, parity, time reversal, and other discrete symmetries – / 13.40.-f Electromagnetic processes and properties – / 14.20.Dh Protons and neutrons –
© Società Italiana di Fisica and Springer-Verlag, 2007
